I'm using the BP Social theme with the classifieds plugin. If I change the colors in my header via "Theme Options->Top Header Settings", the changed values do not appear on the classifieds page (ie. http://yourdomain.com/classifieds - not the member version). The default colors appear instead. This appears to happen on at least BP Community as well, so I'm taking a shot that it's the plugin and entering this here. I did a fresh install on a separate domain (new WP, new plugins, themes, etc) and was able to reproduce it. Let me know if I can provide any additional information. Thanks.