Hm, I'm still seeing the line "background-color: #c9ccd0;" in your site's style.css file, so perhaps when you removed that, the modified file didn't actually get saved/uploaded to your site somehow? After you edit, save and upload the modified style.css file to your site, you may need to hold the Ctrl key when you click Refresh (or Ctrl-F5, same thing), to make sure your browser re-downloads a fresh copy of everything in the page.
If that still doesn't seem to resolve the problem, could you provide the URL of a page where the problem is occurring, so we could examine what might be going on there?