When using a mobile device you might be loading additional css or applying different classes. Just check on your desktop, and run the application in table mode.
When you inspect the elements or backgrounds that are looking weird you can see in the developer tools where that color is coming from. Either remove that definition or override it.
You can go to your application with the suffix: index.html?profile=tablet. I would recommend testing this on the actual server too, just to make sure there aren't any differences.
Also chrome has a really good emulation mode to simulate all types of mobile devices. See also this page for more info about the chrome emulator.