diff --git a/autoload/indent_guides.vim b/autoload/indent_guides.vim
index 3ec756c..aef7b2c 100644
--- a/autoload/indent_guides.vim
+++ b/autoload/indent_guides.vim
@@ -90,15 +90,19 @@ endfunction
 " Automagically calculates and defines the indent highlight colors for
 " terminal vim.
 "
+" NOTE: At the moment this function only supports color numbers and not names.
+" For example, `:hi Normal` containing `ctermbg=0` will work, but
+" `ctermbg=DarkGrey` will not.
+"
 function! indent_guides#cterm_highlight_colors()
-  let hi_search         = indent_guides#capture_highlight('Normal')
+  let hi_normal         = indent_guides#capture_highlight('Normal')
   let ctermbg_pattern   = "ctermbg=\\zs[0-9]\\+\\ze"
-  let hi_search_ctermbg = ''
+  let hi_normal_ctermbg = ''
 
-  " capture the background color from the search highlight
-  let hi_search_ctermbg = matchstr(hi_search, ctermbg_pattern)
-  exe 'hi IndentGuidesEven ctermbg=' . (hi_search_ctermbg + 1)
-  exe 'hi IndentGuidesOdd ctermbg=' . (hi_search_ctermbg + 2)
+  " capture the background color from the normal highlight
+  let hi_normal_ctermbg = matchstr(hi_normal, ctermbg_pattern)
+  exe 'hi IndentGuidesEven ctermbg=' . (hi_normal_ctermbg + 1)
+  exe 'hi IndentGuidesOdd  ctermbg=' . (hi_normal_ctermbg + 2)
 endfunction
 
 "