I'm a bit late to the party and this is probably a stupid question, but why color them at all ? Why not make them black like the rest of the legend ?
I have several old FR keyboards with PBT keycaps and none of them have a different color for the Altgr symbols (the only legends second colors are either grey or green, and that's for the [Impr Ecr
Syst] key.
Well just my 2cents: I thought it would look cool in blue, not so much cool in red, and "normal" in black, but it doesn't bother me or anything, I'm glad I got an international option at all