A casualty of restoring my SNES, were that Power and Reset keys were "bleached".  A few weeks ago while watching a video from Adrian Black (Adrian's Digital Basement), he mentioned seeing a video of someone restoring the color of plastic parts within a car fender by using a heat gun and wondered if the same method could be allied to plastics "bleached" by retrobrighting.

I decided to give it a shot.  I grabbed by 858D and first set it to 110C then, bumped it up to 180C.  I did the Power button first.

Far from perfect, but I would say that's a major improvement. On the Reset button I bumped it to 210C and saw the color changed fast, but I did bump it down a bit, as I found it a bit too easy to start scorching the plastic at that temperature.

I would day the Power button came out better of the two.  I should have removed the keys first and got some practice doing the underside, but I didn't want to risk breaking a clip on one of them again.