Bluey, greeny, purpley lobsters

Hey Matt:

I'm from Maine, and every good Mainer knows live lobsters are a bluey, greeny, purplish color. Why do lobsters turn red when you boil them?

-- Mystified Mainer, the net

The red pigment in a lobster shell is astaxanthin. On the live lobster, footloose and unsuspecting on the ocean floor, the pigment's chemically bound to a protein that dominates the red and makes the critter look bluey, greeny, purplish. When we grab him and throw him screaming into a pot of boiling water, heat destabilizes the protein, it unhitches from the astaxanthin, which then makes the lobster a glowing, expensive red.