diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 2bd5b02..723883f 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -18,117 +18,74 @@
 <summary><b>theme example</b></summary>
 
 To create a custom theme you need to define a colorscheme for each of vim's modes. Each mode has a `fg` and `bg` field for every lualine section.
-This is really easy in lua. Here is and example of a gruvbox theme.
+You can add special effects with `gui`.
+You can provide colors in two ways
+  1. As a table like `{'hexcode', 256_color_code}`
+  2. As a String like `'hexcode'`
+Note : You can use `lualine.util.get_cterm_color(hex_color)` function to genarate 256_color_codes from hex_codes.
+  When method 2 is used 256_color_codes are genarated with that .
+
+Adding theme is really easy in lua. Here is and example of a gruvbox theme.
 
 ```lua
 local gruvbox = {  }
 
 local colors = {
-  black = "#282828",
-  white = '#ebdbb2',
-  red = '#fb4934',
-  green = '#b8bb26',
-  blue = '#83a598',
-  yellow = '#fe8019',
+ -- color format { hex_color, 256_color_code}
+  black        = {"#282828", 235},
+  white        = {'#ebdbb2', 223},
+  red          = {'#fb4934', 203},
+  green        = {'#b8bb26', 143},
+  blue         = {'#83a598', 108},
+  yellow       = {'#fe8019', 209},
 
-  gray = '#a89984',
-  darkgray = '#3c3836',
-
-  lightgray = '#504945',
+  -- color format 'hex_color'
+  gray         = '#a89984',
+  darkgray     = '#3c3836',
+  lightgray    = '#504945',
   inactivegray = '#7c6f64',
 }
 
 gruvbox.normal = {
-  a = {
-    bg = colors.gray,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg  = colors.white,
-  },
-  c = {
-    bg = colors.darkgray,
-    fg = colors.gray
-  }
+  -- gui parameter is optional and behaves the same way as in vim's highlight command
+  a = { bg = colors.gray, fg = colors.black, gui = "bold", },
+  b = { bg = colors.lightgray, fg  = colors.white, },
+  c = { bg = colors.darkgray, fg = colors.gray }
 }
 
 gruvbox.insert = {
-  a = {
-    bg = colors.blue,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.lightgray,
-    fg = colors.white
-  }
+  a = { bg = colors.blue, fg = colors.black, gui = "bold", },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.lightgray, fg = colors.white }
 }
 
 
 gruvbox.visual = {
-  a = {
-    bg = colors.yellow,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.inactivegray,
-    fg = colors.black
-  },
+  a = { bg = colors.yellow, fg = colors.black, gui = "bold", },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.inactivegray, fg = colors.black },
 }
 
 gruvbox.replace = {
-  a = {
-    bg = colors.red,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.black,
-    fg = colors.white
-  },
+  a = { bg = colors.red, fg = colors.black, gui = "bold", },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.black, fg = colors.white },
 }
 
 gruvbox.command = {
-  a = {
-    bg = colors.green,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.inactivegray,
-    fg = colors.black
-  },
+  a = { bg = colors.green, fg = colors.black, gui = "bold", },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.inactivegray, fg = colors.black },
 }
 
+-- you can assign one colorscheme to another, if a colorscheme is
+-- undefined it falls back to normal
 gruvbox.terminal = gruvbox.normal
 
 gruvbox.inactive = {
-  a = {
-    bg = colors.darkgray,
-    fg = colors.gray,
-  },
-  b = {
-    bg = colors.darkgray,
-    fg = colors.gray,
-  },
-  c = {
-    bg = colors.darkgray,
-    fg = colors.gray
-  },
+  a = { bg = colors.darkgray, fg = colors.gray, gui = "bold", },
+  b = { bg = colors.darkgray, fg = colors.gray, },
+  c = { bg = colors.darkgray, fg = colors.gray },
 }
 
 lualine.theme = gruvbox
diff --git a/lua/lualine/highlight.lua b/lua/lualine/highlight.lua
index 532663f..03b6265 100644
--- a/lua/lualine/highlight.lua
+++ b/lua/lualine/highlight.lua
@@ -1,12 +1,16 @@
 local M = {  }
+local utils = require "lualine.utils"
 
-local function highlight (name, foreground, background, special)
+local function highlight (name, foreground, background, gui)
   local command = {
-    'highlight', name,
-    'guifg=' .. foreground,
-    'guibg=' .. background,
-    'gui=' .. (special or 'none'),
-  }
+      'highlight', name,
+      'ctermfg=' .. (foreground[2] or utils.get_cterm_color(foreground)),
+      'ctermbg=' .. (background[2] or utils.get_cterm_color(background)),
+      'cterm=' .. (gui or 'none'),
+      'guifg=' .. (foreground[1] or foreground),
+      'guibg=' .. (background[1] or background),
+      'gui=' .. (gui or 'none'),
+    }
   return table.concat(command, ' ')
 end
 
@@ -28,12 +32,8 @@ function M.create_highlight_groups(theme)
   apply_defaults_to_theme(theme)
   for mode, sections in pairs(theme) do
     for section, colorscheme in pairs(sections) do
-      local special = nil
-      if section == 'a' then
-        special = 'bold'
-      end
       local highlight_group_name = { 'lualine', section, mode }
-      vim.cmd(highlight(table.concat(highlight_group_name, '_'), colorscheme.fg, colorscheme.bg, special))
+      vim.cmd(highlight(table.concat(highlight_group_name, '_'), colorscheme.fg, colorscheme.bg, colorscheme.gui))
     end
   end
 end
diff --git a/lua/lualine/themes/dracula.lua b/lua/lualine/themes/dracula.lua
index c385080..5545f1d 100644
--- a/lua/lualine/themes/dracula.lua
+++ b/lua/lualine/themes/dracula.lua
@@ -1,109 +1,51 @@
-local M = {  }
+local dracula = {}
 
 local colors = {
-  grey       = "#44475a",
-  light_gray = "#5f6a8e",
-  orange     = "#ffb86c",
-  purple     = "#bd93f9",
-  red        = "#ff5555",
-  yellow     = "#f1fa8c",
-  green      = "#50fa7b",
-
-  white      = "#f8f8f2",
-  black      = "#282a36",
+  grey       = {"#44475a", 238},
+  light_gray = {"#5f6a8e", 60 },
+  orange     = {"#ffb86c", 215},
+  purple     = {"#bd93f9", 141},
+  red        = {"#ff5555", 203},
+  yellow     = {"#f1fa8c", 228},
+  green      = {"#50fa7b", 84 },
+  white      = {"#f8f8f2", 255},
+  black      = {"#282a36", 236},
 }
 
-M.normal = {
-  a = {
-    bg = colors.purple,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.light_gray,
-    fg  = colors.white,
-  },
-  c = {
-    bg = colors.grey,
-    fg = colors.white,
-  }
+dracula.normal = {
+  a = { bg = colors.purple, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.light_gray, fg  = colors.white, },
+  c = { bg = colors.grey, fg = colors.white, }
 }
 
-M.insert = {
-  a = {
-    bg = colors.green,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.light_gray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.grey,
-    fg = colors.white,
-  }
+dracula.insert = {
+  a = { bg = colors.green, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.light_gray, fg = colors.white, },
+  c = { bg = colors.grey, fg = colors.white, }
 }
 
-
-M.visual = {
-  a = {
-    bg = colors.yellow,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.light_gray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.grey,
-    fg = colors.white,
-  },
+dracula.visual = {
+  a = { bg = colors.yellow, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.light_gray, fg = colors.white, },
+  c = { bg = colors.grey, fg = colors.white, },
 }
 
-M.replace = {
-  a = {
-    bg = colors.red,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.light_gray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.grey,
-    fg = colors.white,
-  },
+dracula.replace = {
+  a = { bg = colors.red, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.light_gray, fg = colors.white, },
+  c = { bg = colors.grey, fg = colors.white, },
 }
 
-M.command = {
-  a = {
-    bg = colors.grey,
-    fg = colors.white,
-  },
-  b = {
-    bg = colors.light_gray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.purple,
-    fg = colors.white
-  },
+dracula.command = {
+  a = { bg = colors.grey, fg = colors.white, gui = 'bold', },
+  b = { bg = colors.light_gray, fg = colors.white, },
+  c = { bg = colors.purple, fg = colors.white },
 }
 
-M.terminal = M.normal
-
-M.inactive = {
-  a = {
-    bg = colors.white,
-    fg = colors.purple,
-  },
-  b = {
-    bg = colors.grey,
-    fg = colors.purple,
-  },
-  c = {
-    bg = colors.purple,
-    fg = colors.purple,
-  },
+dracula.inactive = {
+  a = { bg = colors.white, fg = colors.purple, gui = 'bold', },
+  b = { bg = colors.grey, fg = colors.purple, },
+  c = { bg = colors.purple, fg = colors.purple, },
 }
 
-return M
+return dracula
diff --git a/lua/lualine/themes/forest_night.lua b/lua/lualine/themes/forest_night.lua
index 892aed5..c4ff70b 100644
--- a/lua/lualine/themes/forest_night.lua
+++ b/lua/lualine/themes/forest_night.lua
@@ -1,121 +1,58 @@
 local forest_night = {}
 
 local colors = {
-  bg0 = "#323d43",
-  bg1 = "#3c474d",
-  bg3 = "#505a60",
-  fg = "#d8caac",
-  aqua = "#87c095",
-  green = "#a7c080",
-  orange = "#e39b7b",
-  purple = "#d39bb6",
-  red = "#e68183",
-  grey1 = "#868d80",
+  bg0    = {"#323d43", 237},
+  bg1    = {"#3c474d", 238},
+  bg3    = {"#505a60", 240},
+  fg     = {"#d8caac", 187},
+  aqua   = {"#87c095", 108},
+  green  = {"#a7c080", 144},
+  orange = {"#e39b7b", 180},
+  purple = {"#d39bb6", 181},
+  red    = {"#e68183", 174},
+  grey1  = {"#868d80", 102},
 }
 
 forest_night.normal = {
-  a = {
-    bg = colors.green,
-    fg = colors.bg0,
-  },
-  b = {
-    bg = colors.bg3,
-    fg = colors.fg,
-  },
-  c = {
-    bg = colors.bg1,
-    fg = colors.fg,
-  },
+  a = { bg = colors.green, fg = colors.bg0, gui = 'bold', },
+  b = { bg = colors.bg3, fg = colors.fg, },
+  c = { bg = colors.bg1, fg = colors.fg, },
 }
 
 forest_night.insert = {
-  a = {
-    bg = colors.fg,
-    fg = colors.bg0,
-  },
-  b = {
-    bg = colors.bg3,
-    fg = colors.fg,
-  },
-  c = {
-    bg = colors.bg1,
-    fg = colors.fg,
-  },
+  a = { bg = colors.fg, fg = colors.bg0, gui = 'bold', },
+  b = { bg = colors.bg3, fg = colors.fg, },
+  c = { bg = colors.bg1, fg = colors.fg, },
 }
 
 forest_night.visual = {
-  a = {
-    bg = colors.red,
-    fg = colors.bg0,
-  },
-  b = {
-    bg = colors.bg3,
-    fg = colors.fg,
-  },
-  c = {
-    bg = colors.bg1,
-    fg = colors.fg,
-  },
+  a = { bg = colors.red, fg = colors.bg0, gui = 'bold', },
+  b = { bg = colors.bg3, fg = colors.fg, },
+  c = { bg = colors.bg1, fg = colors.fg, },
 }
 
 forest_night.replace = {
-  a = {
-    bg = colors.orange,
-    fg = colors.bg0,
-  },
-  b = {
-    bg = colors.bg3,
-    fg = colors.fg,
-  },
-  c = {
-    bg = colors.bg1,
-    fg = colors.fg,
-  },
+  a = { bg = colors.orange, fg = colors.bg0, gui = 'bold', },
+  b = { bg = colors.bg3, fg = colors.fg, },
+  c = { bg = colors.bg1, fg = colors.fg, },
 }
 
 forest_night.command = {
-  a = {
-    bg = colors.aqua,
-    fg = colors.bg0,
-  },
-  b = {
-    bg = colors.bg3,
-    fg = colors.fg,
-  },
-  c = {
-    bg = colors.bg1,
-    fg = colors.fg,
-  },
+  a = { bg = colors.aqua, fg = colors.bg0, gui = 'bold', },
+  b = { bg = colors.bg3, fg = colors.fg, },
+  c = { bg = colors.bg1, fg = colors.fg, },
 }
 
 forest_night.terminal = {
-  a = {
-    bg = colors.purple,
-    fg = colors.bg0,
-  },
-  b = {
-    bg = colors.bg3,
-    fg = colors.fg,
-  },
-  c = {
-    bg = colors.bg1,
-    fg = colors.fg,
-  },
+  a = { bg = colors.purple, fg = colors.bg0, gui = 'bold', },
+  b = { bg = colors.bg3, fg = colors.fg, },
+  c = { bg = colors.bg1, fg = colors.fg, },
 }
 
 forest_night.inactive = {
-  a = {
-    bg = colors.bg1,
-    fg = colors.grey1,
-  },
-  b = {
-    bg = colors.bg1,
-    fg = colors.grey1,
-  },
-  c = {
-    bg = colors.bg1,
-    fg = colors.grey1,
-  },
+  a = { bg = colors.bg1, fg = colors.grey1, gui = 'bold', },
+  b = { bg = colors.bg1, fg = colors.grey1, },
+  c = { bg = colors.bg1, fg = colors.grey1, },
 }
 
 return forest_night
diff --git a/lua/lualine/themes/gruvbox.lua b/lua/lualine/themes/gruvbox.lua
index 68649d8..2cfb452 100644
--- a/lua/lualine/themes/gruvbox.lua
+++ b/lua/lualine/themes/gruvbox.lua
@@ -1,111 +1,53 @@
-local M = {  }
+local gruvbox = {}
 
 local colors = {
-  black = "#282828",
-  white = '#ebdbb2',
-  red = '#fb4934',
-  green = '#b8bb26',
-  blue = '#83a598',
-  yellow = '#fe8019',
-
-  gray = '#a89984',
-  darkgray = '#3c3836',
-
-  lightgray = '#504945',
-  inactivegray = '#7c6f64',
+  black        = {"#282828", 235},
+  white        = {'#ebdbb2', 223},
+  red          = {'#fb4934', 203},
+  green        = {'#b8bb26', 143},
+  blue         = {'#83a598', 108},
+  yellow       = {'#fe8019', 209},
+  gray         = {'#a89984', 144},
+  darkgray     = {'#3c3836', 237},
+  lightgray    = {'#504945', 239},
+  inactivegray = {'#7c6f64', 242},
 }
 
-M.normal = {
-  a = {
-    bg = colors.gray,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg  = colors.white,
-  },
-  c = {
-    bg = colors.darkgray,
-    fg = colors.gray
-  }
+gruvbox.normal = {
+  a = { bg = colors.gray, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.lightgray, fg  = colors.white, },
+  c = { bg = colors.darkgray, fg = colors.gray }
 }
 
-M.insert = {
-  a = {
-    bg = colors.blue,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.lightgray,
-    fg = colors.white
-  }
+gruvbox.insert = {
+  a = { bg = colors.blue, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.lightgray, fg = colors.white }
 }
 
 
-M.visual = {
-  a = {
-    bg = colors.yellow,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.inactivegray,
-    fg = colors.black
-  },
+gruvbox.visual = {
+  a = { bg = colors.yellow, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.inactivegray, fg = colors.black },
 }
 
-M.replace = {
-  a = {
-    bg = colors.red,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.black,
-    fg = colors.white
-  },
+gruvbox.replace = {
+  a = { bg = colors.red, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.black, fg = colors.white },
 }
 
-M.command = {
-  a = {
-    bg = colors.green,
-    fg = colors.black,
-  },
-  b = {
-    bg = colors.lightgray,
-    fg = colors.white,
-  },
-  c = {
-    bg = colors.inactivegray,
-    fg = colors.black
-  },
+gruvbox.command = {
+  a = { bg = colors.green, fg = colors.black, gui = 'bold', },
+  b = { bg = colors.lightgray, fg = colors.white, },
+  c = { bg = colors.inactivegray, fg = colors.black },
 }
 
-M.terminal = M.normal
-
-M.inactive = {
-  a = {
-    bg = colors.darkgray,
-    fg = colors.gray,
-  },
-  b = {
-    bg = colors.darkgray,
-    fg = colors.gray,
-  },
-  c = {
-    bg = colors.darkgray,
-    fg = colors.gray
-  },
+gruvbox.inactive = {
+  a = { bg = colors.darkgray, fg = colors.gray, gui = 'bold', },
+  b = { bg = colors.darkgray, fg = colors.gray, },
+  c = { bg = colors.darkgray, fg = colors.gray },
 }
 
-return M
+return gruvbox
diff --git a/lua/lualine/themes/nord.lua b/lua/lualine/themes/nord.lua
index 892377a..334257f 100644
--- a/lua/lualine/themes/nord.lua
+++ b/lua/lualine/themes/nord.lua
@@ -1,76 +1,37 @@
-local M = {  }
+local nord = {}
 
 local colors = {
-  nord1  = "#3B4252", 
-  nord3  = "#4C566A", 
-  nord5  = "#E5E9F0", 
-  nord6  = "#ECEFF4", 
-  nord7  = "#8FBCBB", 
-  nord8  = "#88C0D0", 
-  nord13 = "#EBCB8B",
-
+  nord1  = {"#3B4252", 237},
+  nord3  = {"#4C566A", 240},
+  nord5  = {"#E5E9F0", 254},
+  nord6  = {"#ECEFF4", 255},
+  nord7  = {"#8FBCBB", 158},
+  nord8  = {"#88C0D0", 159},
+  nord13 = {"#EBCB8B", 221},
 }
 
-M.normal = {
-  a = {
-    fg = colors.nord1,
-    bg = colors.nord8,
-  },
-  b = {
-    fg = colors.nord5,
-    bg = colors.nord1,
-  },
-  c = {
-    fg = colors.nord5,
-    bg = colors.nord3,
-  }
+nord.normal = {
+  a = { fg = colors.nord1, bg = colors.nord8, gui = 'bold', },
+  b = { fg = colors.nord5, bg = colors.nord1, },
+  c = { fg = colors.nord5, bg = colors.nord3, }
 }
 
-M.insert = {
-  a = {
-    fg = colors.nord1,
-    bg = colors.nord6,
-  },
-  b = M.normal.b,
-  c = M.normal.c,
+nord.insert = {
+  a = { fg = colors.nord1, bg = colors.nord6, gui = 'bold', },
 }
 
-
-M.visual = {
-  a = {
-    fg = colors.nord1,
-    bg = colors.nord7,
-  },
-  b = M.normal.b,
-  c = M.normal.c,
+nord.visual = {
+  a = { fg = colors.nord1, bg = colors.nord7, gui = 'bold', },
 }
 
-M.replace = {
-  a = {
-    fg = colors.nord1,
-    bg = colors.nord13,
-  },
-  b = M.normal.b,
-  c = M.normal.c,
+nord.replace = {
+  a = { fg = colors.nord1, bg = colors.nord13, gui = 'bold', },
 }
 
-M.command = M.normal 
-
-M.terminal = M.normal
-
-M.inactive = {
-  a = {
-    fg = colors.nord1,
-    bg = colors.nord8,
-  },
-  b = {
-    fg = colors.nord5,
-    bg = colors.nord1,
-  },
-  c = {
-    fg = colors.nord5,
-    bg = colors.nord1,
-  },
+nord.inactive = {
+  a = { fg = colors.nord1, bg = colors.nord8, gui = 'bold', },
+  b = { fg = colors.nord5, bg = colors.nord1, },
+  c = { fg = colors.nord5, bg = colors.nord1, },
 }
 
-return M
+return nord
diff --git a/lua/lualine/themes/onedark.lua b/lua/lualine/themes/onedark.lua
index aee6df3..f367207 100644
--- a/lua/lualine/themes/onedark.lua
+++ b/lua/lualine/themes/onedark.lua
@@ -1,102 +1,44 @@
-local M = {  }
+local onedark = {}
 
 local colors = {
-  red = "#E06C75",
-  dark_red = "#BE5046",
-  green = "#98C379",
-  yellow = "#E5C07B",
-  dark_yellow = "#D19A66",
-  blue = "#61AFEF",
-  purple = "#C678DD",
-  cyan = "#56B6C2",
-  white = "#ABB2BF",
-  black = "#282C34",
-  visual_black = "NONE",
-  comment_grey = "#5C6370",
-  gutter_fg_grey = "#4B5263",
-  cursor_grey = "#2C323C",
-  visual_grey = "#3E4452",
-  menu_grey = "#3E4452",
-  special_grey = "#3B4048",
-  vertsplit = "#181A1F",
+  red            = {"#E06C75", 168},
+  dark_red       = {"#BE5046", 131},
+  green          = {"#98C379", 114},
+  blue           = {"#61AFEF", 75 },
+  purple         = {"#C678DD", 176},
+  white          = {"#ABB2BF", 249},
+  black          = {"#282C34", 236},
+  visual_grey    = {"#3E4452", 238},
 }
 
-M.normal = {
-  a = {
-    fg = colors.black,
-    bg = colors.green,
-  },
-  b = {
-    fg = colors.white,
-    bg = colors.visual_grey,
-  },
-  c = {
-    fg = colors.green,
-    bg = colors.black,
-  },
+onedark.normal = {
+  a = { fg = colors.black, bg = colors.green, gui = 'bold', },
+  b = { fg = colors.white, bg = colors.visual_grey, },
+  c = { fg = colors.green, bg = colors.black, },
 }
 
-M.insert = {
-  a = {
-    fg = colors.black,
-    bg = colors.blue,
-  },
-  b = {
-    fg = colors.white,
-    bg = colors.visual_grey,
-  },
-  c = {
-    fg = colors.blue,
-    bg = colors.black,
-  },
+onedark.insert = {
+  a = { fg = colors.black, bg = colors.blue, gui = 'bold', },
+  b = { fg = colors.white, bg = colors.visual_grey, },
+  c = { fg = colors.blue, bg = colors.black, },
 }
 
-M.visual = {
-  a = {
-    fg = colors.black,
-    bg = colors.purple,
-  },
-  b = {
-    fg = colors.white,
-    bg = colors.visual_grey,
-  },
-  c = {
-    fg = colors.purple,
-    bg = colors.black,
-  },
+onedark.visual = {
+  a = { fg = colors.black, bg = colors.purple, gui = 'bold', },
+  b = { fg = colors.white, bg = colors.visual_grey, },
+  c = { fg = colors.purple, bg = colors.black, },
 }
 
-M.replace = {
-  a = {
-    fg = colors.black,
-    bg = colors.red,
-  },
-  b = {
-    fg = colors.white,
-    bg = colors.visual_grey,
-  },
-  c = {
-    fg = colors.red,
-    bg = colors.black,
-  },
+onedark.replace = {
+  a = { fg = colors.black, bg = colors.red, gui = 'bold', },
+  b = { fg = colors.white, bg = colors.visual_grey, },
+  c = { fg = colors.red, bg = colors.black, },
 }
 
-M.terminal = M.normal
-M.command = M.normal
-
-M.inactive = {
-  a = {
-    fg = colors.black,
-    bg = colors.white,
-  },
-  b = {
-    fg = colors.white,
-    bg = colors.visual_grey,
-  },
-  c = {
-    fg = colors.white,
-    bg = colors.visual_grey,
-  },
+onedark.inactive = {
+  a = { fg = colors.black, bg = colors.white, gui = 'bold', },
+  b = { fg = colors.white, bg = colors.visual_grey, },
+  c = { fg = colors.white, bg = colors.visual_grey, },
 }
 
-return M
+return onedark
diff --git a/lua/lualine/themes/powerline.lua b/lua/lualine/themes/powerline.lua
index 25ceac9..5fbb558 100644
--- a/lua/lualine/themes/powerline.lua
+++ b/lua/lualine/themes/powerline.lua
@@ -1,88 +1,48 @@
-local M = {  }
+local powerline = {  }
 
 local Colors = {
-  white          = '#ffffff',
-  darkestgreen   = '#005f00',
-  brightgreen    = '#afdf00',
-  darkestcyan    = '#005f5f',
-  mediumcyan     = '#87dfff',
-  darkestblue    = '#005f87',
-  darkred        = '#870000',
-  brightred      = '#df0000',
-  brightorange   = '#ff8700',
-  gray1          = '#262626',
-  gray2          = '#303030',
-  gray4          = '#585858',
-  gray5          = '#606060',
-  gray7          = '#9e9e9e',
-  gray10         = '#f0f0f0',
+  white          = {'#ffffff', 231},
+  darkestgreen   = {'#005f00', 22 },
+  brightgreen    = {'#afdf00', 148},
+  darkestcyan    = {'#005f5f', 23 },
+  mediumcyan     = {'#87dfff', 117},
+  darkestblue    = {'#005f87', 24 },
+  darkred        = {'#870000', 88 },
+  brightred      = {'#df0000', 160},
+  brightorange   = {'#ff8700', 214},
+  gray1          = {'#262626', 235},
+  gray2          = {'#303030', 236},
+  gray4          = {'#585858', 240},
+  gray5          = {'#606060', 241},
+  gray7          = {'#9e9e9e', 245},
+  gray10         = {'#f0f0f0', 252},
 }
 
-M.normal = {
-  a = {
-    fg = Colors.darkestgreen, 
-    bg = Colors.brightgreen,
-  },
-  b = {
-    fg = Colors.gray10,
-    bg = Colors.gray5,
-  },
-  c = {
-    fg = Colors.gray7,
-    bg = Colors.gray2,
-  },
+powerline.normal = {
+  a = { fg = Colors.darkestgreen, bg = Colors.brightgreen, gui = 'bold', },
+  b = { fg = Colors.gray10, bg = Colors.gray5, },
+  c = { fg = Colors.gray7, bg = Colors.gray2, },
 }
 
-M.insert = {
-  a = {
-    fg = Colors.darkestcyan,
-    bg = Colors.white,
-  },
-  b = {
-    fg = Colors.darkestcyan,
-    bg = Colors.mediumcyan,
-  },
-  c = {
-    fg = Colors.mediumcyan,
-    bg = Colors.darkestblue,
-  },
+powerline.insert = {
+  a = { fg = Colors.darkestcyan, bg = Colors.white, gui = 'bold', },
+  b = { fg = Colors.darkestcyan, bg = Colors.mediumcyan, },
+  c = { fg = Colors.mediumcyan, bg = Colors.darkestblue, },
 }
 
 
-M.visual = {
-  a = {
-    fg = Colors.darkred,
-    bg = Colors.brightorange,
-  },
-  b = M.normal.b,
-  c = M.normal.c,
+powerline.visual = {
+  a = { fg = Colors.darkred, bg = Colors.brightorange, gui = 'bold', },
 }
 
-M.replace = {
-  a = {
-    fg = Colors.white,
-    bg = Colors.brightred,
-  },
-  b = M.normal.b,
-  c = M.normal.c,
+powerline.replace = {
+  a = { fg = Colors.white, bg = Colors.brightred, gui = 'bold', },
 }
 
-M.command = M.normal  
-M.terminal = M.normal
-
-M.inactive = {
-  a = {
-    fg = Colors.gray1,
-    bg = Colors.gray5,
-  },
-  b = {
-    fg = Colors.gray1,
-    bg = Colors.gray5,
-  },
-  c = {
-    bg = Colors.gray1,
-    fg = Colors.gray5,
-  },
+powerline.inactive = {
+  a = { fg = Colors.gray1, bg = Colors.gray5, gui = 'bold', },
+  b = { fg = Colors.gray1, bg = Colors.gray5, },
+  c = { bg = Colors.gray1, fg = Colors.gray5, },
 }
 
-return M
+return powerline
diff --git a/lua/lualine/utils.lua b/lua/lualine/utils.lua
index 48c520d..f2e45ca 100644
--- a/lua/lualine/utils.lua
+++ b/lua/lualine/utils.lua
@@ -18,4 +18,301 @@ function M.draw_section(section, separator)
   return ' ' .. table.concat(status, sep) .. ' '
 end
 
+-- color conversion
+local color_table = {
+  -- lookup table for cterm colors
+  -- format {'color_code', {r,g,b}}
+
+  -- Primary 3-bit (8 colors). Unique representation!
+  {'00', {   0,   0,   0 }},
+  {'01', { 128,   0,   0 }},
+  {'02', {   0, 128,   0 }},
+  {'03', { 128, 128,   0 }},
+  {'04', {   0,   0, 128 }},
+  {'05', { 128,   0, 128 }},
+  {'06', {   0, 128, 128 }},
+  {'07', { 192, 192, 192 }},
+
+  -- equivalent "bright" versions of original 8 colors.
+  {'08', { 128, 128, 128 }},
+  {'09', { 255,   0,   0 }},
+  {'10', {   0, 255,   0 }},
+  {'11', { 255, 255,   0 }},
+  {'12', {   0,   0, 255 }},
+  {'13', { 255,   0, 255 }},
+  {'14', {   0, 255, 255 }},
+  {'15', { 255, 255, 255 }},
+
+  -- Strictly ascending.
+  {'16', {   0,   0,   0 }},
+  {'17', {   0,   0,  95 }},
+  {'18', {   0,   0, 135 }},
+  {'19', {   0,   0, 175 }},
+  {'20', {   0,   0, 215 }},
+  {'21', {   0,   0, 255 }},
+  {'22', {   0,  95,   0 }},
+  {'23', {   0,  95,  95 }},
+  {'24', {   0,  95, 135 }},
+  {'25', {   0,  95, 175 }},
+  {'26', {   0,  95, 215 }},
+  {'27', {   0,  95, 255 }},
+  {'28', {   0, 135,   0 }},
+  {'29', {   0, 135,  95 }},
+  {'30', {   0, 135, 135 }},
+  {'31', {   0, 135, 175 }},
+  {'32', {   0, 135, 215 }},
+  {'33', {   0, 135, 255 }},
+  {'34', {   0, 175,   0 }},
+  {'35', {   0, 175,  95 }},
+  {'36', {   0, 175, 135 }},
+  {'37', {   0, 175, 175 }},
+  {'38', {   0, 175, 215 }},
+  {'39', {   0, 175, 255 }},
+  {'40', {   0, 215,   0 }},
+  {'41', {   0, 215,  95 }},
+  {'42', {   0, 215, 135 }},
+  {'43', {   0, 215, 175 }},
+  {'44', {   0, 215, 215 }},
+  {'45', {   0, 215, 255 }},
+  {'46', {   0, 255,   0 }},
+  {'47', {   0, 255,  95 }},
+  {'48', {   0, 255, 135 }},
+  {'49', {   0, 255, 175 }},
+  {'50', {   0, 255, 215 }},
+  {'51', {   0, 255, 255 }},
+  {'52', {  95,   0,   0 }},
+  {'53', {  95,   0,  95 }},
+  {'54', {  95,   0, 135 }},
+  {'55', {  95,   0, 175 }},
+  {'56', {  95,   0, 215 }},
+  {'57', {  95,   0, 255 }},
+  {'58', {  95,  95,   0 }},
+  {'59', {  95,  95,  95 }},
+  {'60', {  95,  95, 135 }},
+  {'61', {  95,  95, 175 }},
+  {'62', {  95,  95, 215 }},
+  {'63', {  95,  95, 255 }},
+  {'64', {  95, 135,   0 }},
+  {'65', {  95, 135,  95 }},
+  {'66', {  95, 135, 135 }},
+  {'67', {  95, 135, 175 }},
+  {'68', {  95, 135, 215 }},
+  {'69', {  95, 135, 255 }},
+  {'70', {  95, 175,   0 }},
+  {'71', {  95, 175,  95 }},
+  {'72', {  95, 175, 135 }},
+  {'73', {  95, 175, 175 }},
+  {'74', {  95, 175, 215 }},
+  {'75', {  95, 175, 255 }},
+  {'76', {  95, 215,   0 }},
+  {'77', {  95, 215,  95 }},
+  {'78', {  95, 215, 135 }},
+  {'79', {  95, 215, 175 }},
+  {'80', {  95, 215, 215 }},
+  {'81', {  95, 215, 255 }},
+  {'82', {  95, 255,   0 }},
+  {'83', {  95, 255,  95 }},
+  {'84', {  95, 255, 135 }},
+  {'85', {  95, 255, 175 }},
+  {'86', {  95, 255, 215 }},
+  {'87', {  95, 255, 255 }},
+  {'88', { 135,   0,   0 }},
+  {'89', { 135,   0,  95 }},
+  {'90', { 135,   0, 135 }},
+  {'91', { 135,   0, 175 }},
+  {'92', { 135,   0, 215 }},
+  {'93', { 135,   0, 255 }},
+  {'94', { 135,  95,   0 }},
+  {'95', { 135,  95,  95 }},
+  {'96', { 135,  95, 135 }},
+  {'97', { 135,  95, 175 }},
+  {'98', { 135,  95, 215 }},
+  {'99', { 135,  95, 255 }},
+  {'100', { 135, 135,   0 }},
+  {'101', { 135, 135,  95 }},
+  {'102', { 135, 135, 135 }},
+  {'103', { 135, 135, 175 }},
+  {'104', { 135, 135, 215 }},
+  {'105', { 135, 135, 255 }},
+  {'106', { 135, 175,   0 }},
+  {'107', { 135, 175,  95 }},
+  {'108', { 135, 175, 135 }},
+  {'109', { 135, 175, 175 }},
+  {'110', { 135, 175, 215 }},
+  {'111', { 135, 175, 255 }},
+  {'112', { 135, 215,   0 }},
+  {'113', { 135, 215,  95 }},
+  {'114', { 135, 215, 135 }},
+  {'115', { 135, 215, 175 }},
+  {'116', { 135, 215, 215 }},
+  {'117', { 135, 215, 255 }},
+  {'118', { 135, 255,   0 }},
+  {'119', { 135, 255,  95 }},
+  {'120', { 135, 255, 135 }},
+  {'121', { 135, 255, 175 }},
+  {'122', { 135, 255, 215 }},
+  {'123', { 135, 255, 255 }},
+  {'124', { 175,   0,   0 }},
+  {'125', { 175,   0,  95 }},
+  {'126', { 175,   0, 135 }},
+  {'127', { 175,   0, 175 }},
+  {'128', { 175,   0, 215 }},
+  {'129', { 175,   0, 255 }},
+  {'130', { 175,  95,   0 }},
+  {'131', { 175,  95,  95 }},
+  {'132', { 175,  95, 135 }},
+  {'133', { 175,  95, 175 }},
+  {'134', { 175,  95, 215 }},
+  {'135', { 175,  95, 255 }},
+  {'136', { 175, 135,   0 }},
+  {'137', { 175, 135,  95 }},
+  {'138', { 175, 135, 135 }},
+  {'139', { 175, 135, 175 }},
+  {'140', { 175, 135, 215 }},
+  {'141', { 175, 135, 255 }},
+  {'142', { 175, 175,   0 }},
+  {'143', { 175, 175,  95 }},
+  {'144', { 175, 175, 135 }},
+  {'145', { 175, 175, 175 }},
+  {'146', { 175, 175, 215 }},
+  {'147', { 175, 175, 255 }},
+  {'148', { 175, 215,   0 }},
+  {'149', { 175, 215,  95 }},
+  {'150', { 175, 215, 135 }},
+  {'151', { 175, 215, 175 }},
+  {'152', { 175, 215, 215 }},
+  {'153', { 175, 215, 255 }},
+  {'154', { 175, 255,   0 }},
+  {'155', { 175, 255,  95 }},
+  {'156', { 175, 255, 135 }},
+  {'157', { 175, 255, 175 }},
+  {'158', { 175, 255, 215 }},
+  {'159', { 175, 255, 255 }},
+  {'160', { 215,   0,   0 }},
+  {'161', { 215,   0,  95 }},
+  {'162', { 215,   0, 135 }},
+  {'163', { 215,   0, 175 }},
+  {'164', { 215,   0, 215 }},
+  {'165', { 215,   0, 255 }},
+  {'166', { 215,  95,   0 }},
+  {'167', { 215,  95,  95 }},
+  {'168', { 215,  95, 135 }},
+  {'169', { 215,  95, 175 }},
+  {'170', { 215,  95, 215 }},
+  {'171', { 215,  95, 255 }},
+  {'172', { 215, 135,   0 }},
+  {'173', { 215, 135,  95 }},
+  {'174', { 215, 135, 135 }},
+  {'175', { 215, 135, 175 }},
+  {'176', { 215, 135, 215 }},
+  {'177', { 215, 135, 255 }},
+  {'178', { 215, 175,   0 }},
+  {'179', { 215, 175,  95 }},
+  {'180', { 215, 175, 135 }},
+  {'181', { 215, 175, 175 }},
+  {'182', { 215, 175, 215 }},
+  {'183', { 215, 175, 255 }},
+  {'184', { 215, 215,   0 }},
+  {'185', { 215, 215,  95 }},
+  {'186', { 215, 215, 135 }},
+  {'187', { 215, 215, 175 }},
+  {'188', { 215, 215, 215 }},
+  {'189', { 215, 215, 255 }},
+  {'190', { 215, 255,   0 }},
+  {'191', { 215, 255,  95 }},
+  {'192', { 215, 255, 135 }},
+  {'193', { 215, 255, 175 }},
+  {'194', { 215, 255, 215 }},
+  {'195', { 215, 255, 255 }},
+  {'196', { 255,   0,   0 }},
+  {'197', { 255,   0,  95 }},
+  {'198', { 255,   0, 135 }},
+  {'199', { 255,   0, 175 }},
+  {'200', { 255,   0, 215 }},
+  {'201', { 255,   0, 255 }},
+  {'202', { 255,  95,   0 }},
+  {'203', { 255,  95,  95 }},
+  {'204', { 255,  95, 135 }},
+  {'205', { 255,  95, 175 }},
+  {'206', { 255,  95, 215 }},
+  {'207', { 255,  95, 255 }},
+  {'208', { 255, 135,   0 }},
+  {'209', { 255, 135,  95 }},
+  {'210', { 255, 135, 135 }},
+  {'211', { 255, 135, 175 }},
+  {'212', { 255, 135, 215 }},
+  {'213', { 255, 135, 255 }},
+  {'214', { 255, 175,   0 }},
+  {'215', { 255, 175,  95 }},
+  {'216', { 255, 175, 135 }},
+  {'217', { 255, 175, 175 }},
+  {'218', { 255, 175, 215 }},
+  {'219', { 255, 175, 255 }},
+  {'220', { 255, 215,   0 }},
+  {'221', { 255, 215,  95 }},
+  {'222', { 255, 215, 135 }},
+  {'223', { 255, 215, 175 }},
+  {'224', { 255, 215, 215 }},
+  {'225', { 255, 215, 255 }},
+  {'226', { 255, 255,   0 }},
+  {'227', { 255, 255,  95 }},
+  {'228', { 255, 255, 135 }},
+  {'229', { 255, 255, 175 }},
+  {'230', { 255, 255, 215 }},
+  {'231', { 255, 255, 255 }},
+
+  -- Gray-scale range.
+  {'232', {   8,   8,   8 }},
+  {'233', {  18,  18,  18 }},
+  {'234', {  28,  28,  28 }},
+  {'235', {  38,  38,  38 }},
+  {'236', {  48,  48,  48 }},
+  {'237', {  58,  58,  58 }},
+  {'238', {  68,  68,  68 }},
+  {'239', {  78,  78,  78 }},
+  {'240', {  88,  88,  88 }},
+  {'241', {  98,  98,  98 }},
+  {'242', { 108, 108, 108 }},
+  {'243', { 118, 118, 118 }},
+  {'244', { 128, 128, 128 }},
+  {'245', { 138, 138, 138 }},
+  {'246', { 148, 148, 148 }},
+  {'247', { 158, 158, 158 }},
+  {'248', { 168, 168, 168 }},
+  {'249', { 178, 178, 178 }},
+  {'250', { 188, 188, 188 }},
+  {'251', { 198, 198, 198 }},
+  {'252', { 208, 208, 208 }},
+  {'253', { 218, 218, 218 }},
+  {'254', { 228, 228, 228 }},
+  {'255', { 238, 238, 238 }},
+}
+
+function M.get_cterm_color(hex_color)
+  local function get_color_distance(color1, color2)
+    -- returns how much color2 deviates from color1
+    local dr = math.abs(color1[1] - color2[1]) / (color1[1]+1) * 100
+    local dg = math.abs(color1[2] - color2[2]) / (color1[2]+1) * 100
+    local db = math.abs(color1[3] - color2[3]) / (color1[3]+1) * 100
+    return (dr + dg + db)
+  end
+
+  local r = tonumber(hex_color:sub(2,3), 16)
+  local g = tonumber(hex_color:sub(4,5), 16)
+  local b = tonumber(hex_color:sub(6,7), 16)
+
+  -- check which cterm color is closest to hex colors in terms of rgb values
+  local closest_cterm_color = 0
+  local min_distance = 10000
+  for _, color in ipairs(color_table) do
+    local current_distance = get_color_distance(color[2], {r,g,b})
+    if current_distance < min_distance then
+      min_distance = current_distance
+      closest_cterm_color = color[1]
+    end
+  end
+  return closest_cterm_color
+end
+
+
 return M