[vim] added visibility option for special and non-text values

README.md

@@ -132,6 +132,7 @@ Set these in your vimrc file prior to calling the colorscheme.
     g:solarized_underline =   1       |   0
     g:solarized_italic    =   1       |   0
     g:solarized_contrast  =   "normal"|   "high" or "low"
+    g:solarized_visibility=   "normal"|   "high" or "low"
     ------------------------------------------------
 
 ### Option Details
@@ -172,6 +173,12 @@ Set these in your vimrc file prior to calling the colorscheme.
     or low does use the same Solarized palette but simply shifts some values up 
     or down in order to expand or compress the tonal range displayed.
 
+*   g:solarized_visibility
+
+    Special characters such as trailing whitespace, tabs, newlines, when
+    displayed using `:set list` can be set to one of three levels depending on 
+    your needs. Default value is `normal` with `high` and `low` options.
+
 Toggle Background Function
 --------------------------
 

colors/solarized.vim

@@ -133,6 +133,7 @@
 " g:solarized_underline =   1       |   0
 " g:solarized_italic    =   1       |   0
 " g:solarized_contrast  =   "normal"|   "high" or "low"
+" g:solarized_visibility=   "normal"|   "high" or "low"
 " ------------------------------------------------
 "
 " OPTION DETAILS
@@ -194,6 +195,13 @@
 " or low does use the same Solarized palette but simply shifts some values up
 " or down in order to expand or compress the tonal range displayed.
 "
+" ------------------------------------------------
+" g:solarized_visibility =  "normal"|   "high" or "low"
+" ------------------------------------------------
+" Special characters such as trailing whitespace, tabs, newlines, when 
+" displayed using ":set list" can be set to one of three levels depending on 
+" your needs.
+"
 " ---------------------------------------------------------------------
 " COLOR VALUES
 " ---------------------------------------------------------------------
@@ -265,6 +273,9 @@ endif
 if !exists("g:solarized_contrast")
     let g:solarized_contrast = "normal"
 endif
+if !exists("g:solarized_visibility")
+    let g:solarized_visibility = "normal"
+endif
 "}}}
 " Colorscheme initialization "{{{
 " ---------------------------------------------------------------------
@@ -615,8 +626,16 @@ exe "hi! Todo"           .s:fmt_bold   .s:fg_magenta.s:bg_none
 "
 "Highlighting groups for various occasions
 "-----------------------------------------
-exe "hi! SpecialKey"     .s:fmt_none   .s:fg_base02 .s:bg_none
+if      (g:solarized_visibility=="high")
+exe "hi! SpecialKey"     .s:fmt_revr   .s:fg_red    .s:bg_none
+exe "hi! NonText"        .s:fmt_bold   .s:fg_base1  .s:bg_none
+elseif  (g:solarized_visibility=="low")
+exe "hi! SpecialKey"     .s:fmt_bold   .s:fg_base02 .s:bg_none
 exe "hi! NonText"        .s:fmt_bold   .s:fg_base02 .s:bg_none
+else
+exe "hi! SpecialKey"     .s:fmt_bold   .s:fg_red    .s:bg_none
+exe "hi! NonText"        .s:fmt_bold   .s:fg_base01 .s:bg_none
+endif
 exe "hi! Directory"      .s:fmt_none   .s:fg_blue   .s:bg_none
 exe "hi! ErrorMsg"       .s:fmt_revr   .s:fg_red    .s:bg_none
 exe "hi! IncSearch"      .s:fmt_revr   .s:fg_yellow .s:bg_none