Basically, with the stock cluster overlay you are sol. It uses a film behind the overlay to produce the color you see. You can get an aftermarket overlay and some leds to replace the incandescent bulbs the stock cluster uses.
http://www.blackcatcustom.com/Firebird%20Trans%20Am.htm They have an overlay and led bulb replacement kit below it. They say if you want white leds, they can optimize the overlay to suite your color choice.
Changing an overlay isn't that bad, you will just have to take your time to realign the needles. While they are off, you can wet sand the color off of the back of them and paint them white or whatever color/design you want.
