Mac is case-insensitive by default. Rename the original Slate.vim into

Slate0.vim

colors/Slate0.vim

@@ -0,0 +1,11 @@
+
+" It's based on:
+runtime colors/Dark.vim
+
+let g:colors_name = "SlateBG"
+
+hi Normal guibg=DarkSlateGrey guifg=AntiqueWhite1
+hi NonText guibg=#1F3F3F
+
+"hi Cursor guifg=AntiqueWhite1 guibg=bg gui=reverse
+hi Cursor guibg=salmon3

colors/slate.vim

@@ -0,0 +1,56 @@
+"%% SiSU Vim color file
+" Slate Maintainer: Ralph Amissah <[email protected]>
+" (originally looked at desert Hans Fugal <[email protected]> http://hans.fugal.net/vim/colors/desert.vim (2003/05/06)
+:set background=dark
+:highlight clear
+if version > 580
+ hi clear
+ if exists("syntax_on")
+ syntax reset
+ endif
+endif
+let colors_name = "slate"
+:hi Normal guifg=White guibg=grey15
+:hi Cursor guibg=khaki guifg=slategrey
+:hi VertSplit guibg=#c2bfa5 guifg=grey40 gui=none cterm=reverse
+:hi Folded guibg=black guifg=grey40 ctermfg=grey ctermbg=darkgrey
+:hi FoldColumn guibg=black guifg=grey20 ctermfg=4 ctermbg=7
+:hi IncSearch guifg=green guibg=black cterm=none ctermfg=yellow ctermbg=green
+:hi ModeMsg guifg=goldenrod cterm=none ctermfg=brown
+:hi MoreMsg guifg=SeaGreen ctermfg=darkgreen
+:hi NonText guifg=RoyalBlue guibg=grey15 cterm=bold ctermfg=blue
+:hi Question guifg=springgreen ctermfg=green
+:hi Search guibg=peru guifg=wheat cterm=none ctermfg=grey ctermbg=blue
+:hi SpecialKey guifg=yellowgreen ctermfg=darkgreen
+:hi StatusLine guibg=#c2bfa5 guifg=black gui=none cterm=bold,reverse
+:hi StatusLineNC guibg=#c2bfa5 guifg=grey40 gui=none cterm=reverse
+:hi Title guifg=gold gui=bold cterm=bold ctermfg=yellow
+:hi Statement guifg=CornflowerBlue ctermfg=lightblue
+:hi Visual gui=none guifg=khaki guibg=olivedrab cterm=reverse
+:hi WarningMsg guifg=salmon ctermfg=1
+:hi String guifg=SkyBlue ctermfg=darkcyan
+:hi Comment term=bold ctermfg=11 guifg=grey40
+:hi Constant guifg=#ffa0a0 ctermfg=brown
+:hi Special guifg=darkkhaki ctermfg=brown
+:hi Identifier guifg=salmon ctermfg=red
+:hi Include guifg=red ctermfg=red
+:hi PreProc guifg=red guibg=white ctermfg=red
+:hi Operator guifg=Red ctermfg=Red
+:hi Define guifg=gold gui=bold ctermfg=yellow
+:hi Type guifg=CornflowerBlue ctermfg=2
+:hi Function guifg=navajowhite ctermfg=brown
+:hi Structure guifg=green ctermfg=green
+:hi LineNr guifg=grey50 ctermfg=3
+:hi Ignore guifg=grey40 cterm=bold ctermfg=7
+:hi Todo guifg=orangered guibg=yellow2
+:hi Directory ctermfg=darkcyan
+:hi ErrorMsg cterm=bold guifg=White guibg=Red cterm=bold ctermfg=7 ctermbg=1
+:hi VisualNOS cterm=bold,underline
+:hi WildMenu ctermfg=0 ctermbg=3
+:hi DiffAdd ctermbg=4
+:hi DiffChange ctermbg=5
+:hi DiffDelete cterm=bold ctermfg=4 ctermbg=6
+:hi DiffText cterm=bold ctermbg=1
+:hi Underlined cterm=underline ctermfg=5
+:hi Error guifg=White guibg=Red cterm=bold ctermfg=7 ctermbg=1
+:hi SpellErrors guifg=White guibg=Red cterm=bold ctermfg=7 ctermbg=1