I just picked up a gameboy color in a trade, and thought I'd try my hand at front-light modding it. I've been reading up on my options, and without sacking existing GBA SP's to harvest their frontlights, I ordered the
kitch-bent kit (which are now back in stock)
The picture of the screen they have there doesn't look so great, but after a bit of googling I found a few links that have promising results, using the aforementioned LOCA curing method.
The relevant page:
http://chipmusic.org/forums/topic/14582/game-boy-color-frontlighting-101-mod/
I've been experimenting with a friend on a mod which involves a custom made diffuser panel and LOCA (liquid optically clear adhesive) to cut down on the glare and internal reflections. The results have been somewhat underwhelming so far, but the concept is proven in the sense that Amazon's designers did the same thing with the Kindle Paperwhite, and that look fantastic. So we're hopeful we can figure it out.
Did you get anywhere with this? I noticed you contributed to the link above, and I was looking into options that can minimize the amount of glare from the light bouncing around inside the GBC.
I found this guy's page that has some interesting details on the diffusion screen he used on a his mod (using a GBA SP light panel):
http://www.mylkstuff.com/page87.htm#.VD70vPl4ryA
I'm going to look into more options as I wait for my light kit to arrive.
But if anyone has any more info on minimizing the internal glare, please share!