laser beams

laser beam colors
They aren't. But red diode lasers are easier and cheaper to make than other types.
Some other very common laser colors are green & blue. There are also lasers with wavelengths in the infrared, lasers that emit microwaves, and even x-ray lasers.
Many colors are available with gas lasers, and any possible color in the rainbow can be produced with dye lasers (which use a liquid organic dye as the lasing medium).

Right. Helium-neon lasers are red, ruby lasers are pink or red, argon lasers are blue/green, etc.