I've scanned my Gameboy Color and created a MESS bezel and lay file - you can drop it right in the MESS artwork folder. I hope it's okay to upload MESS artwork here. If not, please remove this post as I've also uploaded it to the MESS forums, but I figured it would get more exposure here.
The bezel was scanned at 1200 DPI so the image is pretty large and the archive is 35 megs. I only wanted to do this once and didn't want this to become obsolete in 5-10 years when much higher resolution monitors are available. I thought about scanning at 2400 DPI but thought that would be overkill :-). I have more coming soon: A Gameboy Pocket (black), Gameboy Advance (purple), 2 Gameboy Advance SP's (black and purple), Nintendo DS (gray), and a GameGear. Here's a small taste of the Gameboy Color: