Added an option `g:gruvbox_foreground_guisp` to have guisp color override foreground color

colors/gruvbox.vim

@@ -41,6 +41,9 @@ endif
 if !exists('g:gruvbox_underline')
 	let g:gruvbox_underline=1
 endif
+if !exists('g:gruvbox_foreground_guisp')
+	let g:gruvbox_foreground_guisp=0
+endif
 
 if !exists('g:gruvbox_italicize_comments')
 	let g:gruvbox_italicize_comments=1
@@ -228,7 +231,11 @@ function! s:HL(group, fg, ...)
 
 	let histring = 'hi ' . a:group . ' '
 
-	if strlen(a:fg)
+	" if (Foreground override enabled) && (    We were passed a guisp value     )
+	if g:gruvbox_foreground_guisp != 0 && a:0 >= 3 && strlen(a:3) && a:3 != 'none'
+		let c = get(s:gb, a:3)
+		let histring .= 'guifg=#' . c[0] . ' ctermfg=' . c[1] . ' '
+	elseif strlen(a:fg)
 		if a:fg == 'fg'
 			let histring .= 'guifg=fg ctermfg=fg '
 		elseif a:fg == 'bg'