I remember participating in a thread like this before when I first did it. (few years ago) This one was done with the color change paint.
It did not mess up the temps, that said i think there are a few reasons why.
1-the color coat (thick)is only on the top plate
2-the black is a VERY light coat of flat black LACQUER (enamel goes on much thicker
3-Remember the alum fins are usually coated with a clear coat
4-I figured there was a reason the SR 71 wasent chrome plated