I would never risk it. When I have my sweethearts in a tent with my friends gliders, I only 'mark' the Standard Grays as hers are Standards. I use 'Scotch Tape' and a very little amount to wrap around my Sugar's tail. I never use a whole 'wad' of it. Just enough so you can see that it is her. NEVER do this in the cage though, only if it's like, playtime for instance. If you know your gliders well enough you should be able to tell them apart by personality if nothing else.
I trimmed the fur in a little band around the tail of my one glider. It doesn't hurt them in anyway, and they don't seem to notice. You don't have to scalp them bald, just take the trimmer and notch the hair.