Phycoerythrin is a red pigment found in red algae and some cyanobacteria. It absorbs light in the blue and green regions of the electromagnetic spectrum, with peak absorbance around 495-565 nm.

Here's a breakdown:

* Blue light: Wavelengths around 450-495 nm are strongly absorbed by phycoerythrin.

* Green light: Wavelengths around 500-565 nm are also absorbed, but to a slightly lesser extent than blue light.

* Red light: Wavelengths above 600 nm are not absorbed by phycoerythrin.

Why is this important?

Phycoerythrin's absorption properties allow red algae and cyanobacteria to thrive in deep waters where sunlight is scarce. Blue and green light penetrate deeper into the ocean than other wavelengths, making phycoerythrin a valuable tool for photosynthesis in these environments.