i would say white then, cos blue and red arent that complementing. That or try and find dark smoked lenses - legal of course. Should complement the black trims (I assume the bumpers etc arent colour coded)
Hmm, I fail to see why that matters? If it's dark you can't see the colour especially not if you have the glare of headlights!
The whole issue of replacement bulbs isn't as simple as that I don't think, you need to make sure they don't require anymore power (overheating casuing damages wiring etc.) and that they are set up not to damage the view of other drivers - a lot of people don't consider this hence why you see so many cars that blind you WITHOUT main beam on.