I got bored and opened up a set of lights to see how the duplicolor black chrome paint would work. Light output is about the same. they are next to a set of nice clear ones.
I heated the light to soften the silicone that held the lens on ( you could pry it off cold if you went slowly ). I removed the old silicone from the lens; very time consuming. I cleaned the chrome reflector with dawn dish soap and a really worn out red scotch brite. lightly touching the surface. sprayed a few coats of the base, waiting about 5 minutes between. then about 20 minutes later sprayed 2 coats of the clear. I used a black silicone ( not gasket maker ) to glue it back together.
The lens remains clear so the light is about the same. I wet sand the lens with 400/ 600/ 1000/ 1500 then use 3M polishing compound to make sure its clear. The best effect is when you turn them on and they change from black to bright white. Not a big investment. I have done 2 front ovals, 2 headlights, 3 sets of fogs and I have over half a can left of the base.