For those who would like a monochromatic look to the tail/brake lights/turn signal lights, it is easily done. The tail light of my Porsche 928 GTS had a yellow portion that was nearly 50% of the quite large tail light. That contrast did not suit my eye (or of a few other owners).
An owner in the Dallas TX area was the first to change his to monochrome. The procedure is: Clean the turn signal area very well, either mask it well, or remove the turn signal lens. Spray the lens with Testor model paint. I found that to match mine, very thin coats alternating between 'candy apple red' and 'hot rod red' gave a perfect match to the color of the brake/tail light lens. This is an enamel, so if it needs to be removed, enamel paint thinner will remove it without damaging plastic.
I will probably change the color of my 3.0 CS lenses this winter.