In humans melanin helps in colouration but in chameleons what help in their colour changes?

Question

Colouration in humans and chameleons

Answer 1

***chromatophores, which are specialized cells that contain pigment, analogous to melanin in humans. They're basically sacs of pigment that are made visible/invisible by muscles around their circumference. Those muscles are under direct control of neurons connected to the motor regions of the brain.