Question

What wavelengths of the light spectrum are absorbed by red pigment?

Answer 1

Short answer: all wavelengths, except red.

Explanation:

Longer answer: The word 'red' encompasses a lot of colours, from 'almost orange' to 'scarlet' to 'almost purple'.

Usually we call any light with a wavelength of more than about 650 nm 'red', which means that a red pigment would absorb anything below that.