The primary light colours are red blue and green. They can be mixed, as follows, to form secondary light colours:
red + green = yellow
red + blue = magenta
blue + green = cyan

By using a prism, white light can be separated into all the different (dispersion) colours that make up white light. These are (starting with long wavelength):
red, orange, yellow, green, blue, indigo, violet

Reflection:
The angle of incident always equals the angle of reflection. These are measured against the normal which is an imaginary straight line at a right angle to the mirror.

Refraction:
Refraction is the process that occurs when light travels from one material to another, it is either speed up or slowed down. This has an effect on the light and bends it. The denser the material, the slower the speed of light.