Function interpolate

interpolate(color1: Color, color2: Color, t: number): Color
Given two colors, interpolate between them using a t value between 0 and 1. 0 returns color1, 1 returns color2, and anything in between returns a mixture.
Parameters
- color1: Color
  first color
- color2: Color
  second color
- t: number
  t value between 0 and 1
Returns Color
interpolated color