The pigment proteins filter out harmful UV rays. Corals make more of these pigments when they’re exposed to very bright light. It’s similar to how a person with fair skin responds to the sun. More pigment means better protection from harmful UV rays of the sun.
What is the color of corals, usually is it red?
Red tides can take on the appearance of a variety of colors from brown to burgundy, to bright red, and even yellow. The color of a bloom depends on which phytoplankton species is blooming, along with other factors such as light intensity and the angle of the sun shining on the water.