After getting the wheel off and thinking about it, I decided to paint the shield and caliper black instead of the originally intended aluminum color. I thought this would give nicer contrast to the rims, plus I had an ulterior motive thinking "brake dust black" color might be a lot easier to keep respectable looking.
Back to the auto parts store for a can of black Duplicolor High Heat.
Here it is prepped for painting the black parts. I covered the area of the caliper (left side on this one) where the sensors are attached so I didn't screw something up, and the outer side is not really visible with the wheel installed anyway. Probably couldn't get away with that if I was using a more dramatic color though.