Most of the generic carbon road bikes look poor because they are bought by people who don’t have a clue how to set them up: inline seatposts, lots of stem spacers, bars turned upwards, short stems that’re upside down etc. etc. They may aswell have bought as hybrid.
As for mountain bikes; any of those cotic bfe’s that were blue/green/purple. Horrid colours, and they all seem to be bought by slightly thick northern men with no taste whatsoever. Look at this one for example. White parts?? On an MTB??
I think tasteful white parts can really set off a bike, I’ve always been a fan of white wheels on bikes, cars, motorbikes, whatever. Agree that cotic is a bit OTT though, you can have too much white.