Overwrite colorscheme syntax highlighting

Question

/* This is coming directly from Molokai's issue #36. */

The problem

Molokai is a very nice theme for Vim but it has a terrible vimdiff highlighting (see left split, last 5 lines). + are not green and - are not red.

I've been suggested by justinmk@GitHub to use the following ~/.vimrc (here's the gist).

syntax enable
let s:color_override_dark = '
    \ if &background == "dark"
    \ | hi StatusLine    guifg=#000000 guibg=#ffffff gui=NONE  ctermfg=16 ctermbg=15     cterm=NONE
    \ | hi CursorLine    guibg=#293739 ctermbg=236
    \ | hi PmenuSel      guibg=#0a9dff guifg=white   gui=NONE  ctermbg=39 ctermfg=white  cterm=NONE
    \ | hi PmenuSbar     guibg=#857f78
    \ | hi PmenuThumb    guifg=#242321
    \ | hi WildMenu      gui=NONE cterm=NONE guifg=#f8f6f2 guibg=#0a9dff ctermfg=255 ctermbg=39
    \ | hi DiffAdd       guifg=#ffffff guibg=#006600 gui=NONE  ctermfg=231  ctermbg=22   cterm=NONE 
    \ | hi DiffChange    guifg=#ffffff guibg=#007878 gui=NONE  ctermfg=231  ctermbg=30   cterm=NONE 
    \ | hi DiffDelete    guifg=#ff0101 guibg=#9a0000 gui=NONE  ctermfg=196  ctermbg=88   cterm=NONE 
    \ | hi DiffText      guifg=#000000 guibg=#ffb733 gui=NONE  ctermfg=000  ctermbg=214  cterm=NONE 
    \ | hi MatchParen    guifg=NONE   guibg=NONE gui=underline ctermfg=NONE ctermbg=NONE cterm=underline
    \ | endif
    \'

if has('vim_starting') "only on startup
  exe 'autocmd ColorScheme * '.s:color_override_dark
  " expects &runtimepath/colors/{name}.vim.
  silent! colorscheme molokai
endif

which unfortunately does not work for some reasons. Can someone point out what has been done wrongly?

---

The solution

Inserting the following code into ~/.vimrc fixes the problem stated above.

colorscheme molokai
" Better gitcommit messages
hi diffAdded   ctermbg=NONE ctermfg=46  cterm=NONE guibg=NONE guifg=#00FF00 gui=NONE
hi diffRemoved ctermbg=NONE ctermfg=196 cterm=NONE guibg=NONE guifg=#FF0000 gui=NONE
hi link diffLine String
hi link diffSubname Normal

And here we have a before / after :)

Further information

It is possible to remap F10 to *show me what syntax is this*. Then, one can modify what s/he feels needs some adjustments, as I've done for the 'strong' diffLine and to the 'green' diffSubname.

Answer 1

DiffAdd and DiffDelete are only used when actually performing a diff ($ vim -d foo.txt bar.txt, $ vimdiff foo.txt bar.txt, $ git mergetool, etc.); those highlight groups are totally irrelevant, here.

The highlight groups used for added and deleted lines when reading a diff file are diffAdded and diffRemoved.

Adding the lines below between line 272 and line 274 of molokai.vim should fix your problem:

hi diffAdded   ctermbg=NONE ctermfg=108 cterm=NONE guibg=NONE guifg=#87af87 gui=NONE
hi diffRemoved ctermbg=NONE ctermfg=131 cterm=NONE guibg=NONE guifg=#af5f5f gui=NONE

(Those are the colors used in my own colorscheme, use the ones you want.)