Black may be common, but to me it's still a bad ass color for a gaming rig case.
That being said, what I'd like to see is the option to switch between colors for the LED lights on the fans and elsewhere. For example - a knob on the back of the case that you could use to switch between Red, Green and Blue for all LEDS lights in the case. Perhaps even an All option that displays all 3 colors simultaneously.
Many of us game with the lights off at night, which is why I propose providing options for the colors of the LEDS, not the case itself.