On my car (all black paintwork) and rims is a mix of silver (not sure if metal but not shiny chrome) and black. The valve stems are black rubber. They were covered with green caps (car arrived like this - only bought it a few weeks ago) and about half of the caps were missing. So, if they were green BECAUSE they were filled with nitrogen, and if not, soon), I wanted a set of capital letters that didn't collide, but was still informative. You have met all the requirements exactly. The lower total was that it would be better to make a set of 5 (one as a spare) or 6 (in case one is lost). But for the price, I'll probably just buy a second set.