ViperGTS, on the colour of the cage?
It's not such an easy call.......
In a white car a black cage, looks aftermarket and would look discrete, you would have to be close to the car to notice.
Having said that unusually on a CS-S it may work in contrast to the black roof?
Red, goes with the GTi signature theme, matches calipers and grill stripe etc...
However, I would paint the cage in body colour white, even though it is a bolt in, it looks more integrated with the car body shell and less aftermarket, also not quite as glaringly obvious as a red cage stuck in the back.
As I said, no obvious answer and red harnesses are a must anyway, red harness on a white cage, has a hint of 996 GT3 RS about it?