43cd359e6c
I changed the part about the issue where Limelight is not be able to calculate the color, to make it clearer what we are suppose to do to fix the issue when it happen, avoiding the confusion of how do i "define it" where do i "define it" "which part of this code fix the issue ?" i tried to answer those question to the best of my ability, also making clear that the example are individual line example.
limelight.vim 
Hyperfocus-writing in Vim.
Best served with Goyo.vim. Works on 256-color terminal or on GVim.
Usage
Limelight [0.0 ~ 1.0]- Turn Limelight on
Limelight!- Turn Limelight off
Limelight!! [0.0 ~ 1.0]- Toggle Limelight
Limelight for a selected range
You can invoke :Limelight for a visual range. There are also <Plug>
mappings for normal and visual mode for the purpose.
nmap <Leader>l <Plug>(Limelight)
xmap <Leader>l <Plug>(Limelight)
Options
For some color schemes, Limelight may not be able to calculate the color for
dimming down the surrounding paragraphs. In that case, you need to define it manually
in your .vimrc file. you can do so by adding g:limelight_conceal_ctermfg= or g:limelight_conceal_guifg=
followed by the clor of your choosing. (To see the available color for each you can type ":help cterm-colors" or ":help gui-colors".)
Here's some line examples of what it should look like, but feel free to change the color name to suite your needs.
" Color name (:help cterm-colors) or ANSI code
let g:limelight_conceal_ctermfg = 'gray'
" Or
let g:limelight_conceal_ctermfg = 240
" Color name (:help gui-colors) or RGB color
let g:limelight_conceal_guifg = 'DarkGray'
" Or
let g:limelight_conceal_guifg = '#777777'
"Some other example of line you might whant to try --->
" Default: 0.5
let g:limelight_default_coefficient = 0.7
" Number of preceding/following paragraphs to include (default: 0)
let g:limelight_paragraph_span = 1
" Beginning/end of paragraph
" When there's no empty line between the paragraphs
" and each paragraph starts with indentation
let g:limelight_bop = '^\s'
let g:limelight_eop = '\ze\n^\s'
" Highlighting priority (default: 10)
" Set it to -1 not to overrule hlsearch
let g:limelight_priority = -1
Goyo.vim integration
autocmd! User GoyoEnter Limelight
autocmd! User GoyoLeave Limelight!
Acknowledgement
Thanks to @Cutuchiqueno for suggesting the idea.
License
MIT