Answer:
When the waves reflected from the inner and outer surface combine they will interfere with each other, removing or reinforcing some parts of white light by destructive or constructive interference. ... This results in color.
Explanation:
this is what we studied
so basically there is like a surface
and 2 different waves coming out of the same source
they will combine and start removing parts of the white light (which originally consists of 6 to 7 colors)
results in showing these colors
