Question

Why does laser beam might appear blue and another laser beam might appear red?

Answer 1

Answer: D. Each laser beam is made up of one specific wavelength of light.

Explanation: Lasers are in one specific color because it is made up of one specific wavelength of light. So the blue wavelength is blue and the red wavelength is red.

Answer 2

One thing about a laser is that the light it puts out is all one single sharp
color (wavelength) of light with no other wavelengths mixed in with it.
That wavelength is a different one for the different kinds of material
that are used to do the "lasing" ... generating the light. There are a
couple of different wavelengths of infrared lasers, and several different
types of lasers in the visible range.