I've just logged out again and I'm looking at a white background with black text - with sort of beige/oatmeal colored sidebar and comment title bars - and that's the style I changed the community to earlier this year. If you're not seeing that, I'm guessing you have your IJ account set to use your own defaults, even in communities.
(psst...if you have more technical questions, email me, okay? bethbethbeth at gmail *g*)