Hey. Mark(msmont) is right. I changed the stock green lights to blue, but just in the AC controls. I didn't have to change the stock stereo or gauge cluster because I have an aftermarket deck(Kenwood Z727) and 5-color indiglos. I really just changed the backlighting for the AC controls, the ones that light up the little symbols at night and the HI/LO fan AC fan settings and temp controls. The stock green LEDs remain.
I used blue panasonic LED's that I purchased from Digikey. I also had to build a custom power supply to power the LED's at a certain voltage. Off the top of my head, I believe it's around 4v. I removed the stock Toyota bulbs and used the holders for the blue LEDs. It gives the dash a nice effect, the AC controls light up in blue/green and the Kenwood Z727 lights up in matching blue/green, the blue lighting also matches the blue display from my HKS turbo timer Type1 mounted where the TRAC control used to be. Blue lighting dominates the dash. It's a really cool effect and I am very happy with how it turned out. I'll try and have pics up soon.
Alan