Get the treesitter diff parser colors working nicely by defining some colors and mixing it with the classic syntax

vim/colors/darkcloud.vim

@@ -409,6 +409,13 @@ endfun
         hi! link @number.scss @number.css
         hi! link @property.scss @property.css
         hi! link @variable.scss @variable.css
+
+        "diff
+        call s:C("@attribute.diff",g:cYellow,"","")
+        call s:C("@constant.diff",g:cBlue,"","italic")
+        call s:C("@diff.minus",g:cYellow,"","")
+        call s:C("@diff.plus",g:cBlue,"","")
+        call s:C("@function.diff",g:cRed,"","bold")
     endif
 "}}}
 

vim/config/plugins/nvim-treesitter.lua

@@ -18,7 +18,7 @@ if (vim.g.enabletreesitter == 1) then
         highlight = {
             enable = true,
             disable = { "gitcommit", "markdown" },
-            additional_vim_regex_highlighting = { "scss" },
+            additional_vim_regex_highlighting = { "diff", "scss" },
         },
 
         textobjects = {