changing background color

Not sure what's going wrong here. I want to change the lighter grey color of the center box here:
https://www.glasscrafts.com.au/store

I'm in the custom template (darkness) stylesheet, and I've changed the #mainWrapper background-color to #18003c, I can even see it there on the server so I know I'm in the right file. But instead of my nice dark blue I'm still getting this grey.

(Yes I know the configure.php file is still "writable". I've changed the permissions to 644 but I'm still getting this poxy message. But that's another forum.)

You have stylesheet.css
and
stylesheet_ori.css

Your ZC will use both sheets - and will read ORI after the standard one, so any styles defined in the default sheet will be cancelled out by ORI.

Unless you have a good reason for stylesheet_ori.css REMOVE, or RENAME the file ext to TXT, or similar so it's not seen as a css file.

To change 644 to 444 you need to log into your c-panel via your host account.

I'd recommend removing it completely. By all means take a back-up if that makes you feel more comfortable, but keep it somewhere off your site. This is a good example of why mixing backup files with live files is a really bad idea. There's a ton of other places in Zen Cart where doing this will have more extreme consequences.

Geez, thanks for this. And I thought I was being ultra-careful, keeping originals of any file I had changed. I've done this dozens of times, and will now go through and change them all to txt files.