The Tire (Pressure) Is High But I'm Holding On

When it comes to tires (or tyres for people outside of America), black is the safest choice. Yes, for once black is acceptable to be on your bike! That is not to say colors are bad for tires, but there is a narrow range of choices that look good. For example, gumwall tires are hot, period. They will work with any bike. White tires are not recommended, because they scream out "hipster", but see below for an exception.

Boonen in a skinsuit and gumwalls. I honestly cannot find anything wrong with this picture.

They look good on mountain bikes too!

White tires are usually a no-go, but natural white Dugasts for cyclocross are to die for. 

In the spring classics, you will see lots of green tires wrapped around box-section rims, and you can be assured that those are Vittoria Paves. Never mind the green doesn't match the bike, they look sexy. Another tire that looks great without matching the bike is a pair of digital blue Michelin PR3s. Clinchers are a rare sight in the professional peloton, but the Michelins have been used by Euro teams like AG2R (though not the most stylish team ever, but we'll let that slide).

Ready for the cobbles.

Especially classy when coupled with 32-hole box section rims.

Yeah, those are actually clinchers.

The most important rule to follow is balance. If a bike is primarily red, equipped with a red saddle and red bar tape, a pair of red tires would be overkill. Why would you have a red saddle and bar tape in the first place? On the other hand, if a bike is primarily white with red accents, tires with red sidewalls could work, though I would still go with black tires or one of the colors mentioned earlier. Mismatching tire colors is not good, unless you really have to or just want to look like a fixie hipster.