|For a pretty price you can order all kinds of interesting Schrader and Presta caps. |
Most of these are courtesy of Amazon, in case any in this collection appeal to you.
A hula girl on your bike, perhaps?
I understand why tubes are black. But could suppliers provide colored caps? They wouldn't have to match between wheels, just be offered in another color, not black or grey. And, for that matter, would you pay extra—presuming colors cost more to manufacture—for this option? I'd gladly pay 50 cents more per tube to keep caps on my bicycles.