I tried it and it didn’t work – I think because it’s being overridden by the color at Lines 2919-2924, which specifies the color for #welcome. I was trying to get Welcome-Wide to have a white background and Welcome Features 1-3 to have a blue background, but now I see that it looks like Welcome-Wide and the Welcome Features are all governed under #welcome.
I think I may be able to do what I want there another way though. Thanks!