Just wanted to share a success story. I've retrobright 2 other cases using the salon developer creme, covered in cling wrap in the sun. (admittedly inspired by the 8 Bit Guy on youtube). While thing have gotten brighter, I've had some trouble with uneven coloring and some marble-like texture.
This time did things a bit differently. I applied the same cream with a disposable foam brush, and re-applied/evened out the coats every 5 minutes or so. This was on a very clear, hot (well, for the northwoods anyway) day, and it took about 45 minutes probably. I was able to add more cream where needed and got some nice even results. No cling wrap or anything used.
Before: Compare to the not-too faded keyboard

Before: The lighting actually makes it look a bit more gray than it was, but you can see the difference where the Quicktime sticker was

After: matches the keyboard pretty well

After: you can only notice the sticker spot if you look really close, even sitting at desk it's hardly noticeble

This time did things a bit differently. I applied the same cream with a disposable foam brush, and re-applied/evened out the coats every 5 minutes or so. This was on a very clear, hot (well, for the northwoods anyway) day, and it took about 45 minutes probably. I was able to add more cream where needed and got some nice even results. No cling wrap or anything used.
Before: Compare to the not-too faded keyboard

Before: The lighting actually makes it look a bit more gray than it was, but you can see the difference where the Quicktime sticker was

After: matches the keyboard pretty well

After: you can only notice the sticker spot if you look really close, even sitting at desk it's hardly noticeble

