Color of algae

Lyngbya is yellow because of the pigment scytonemin. On the other hand, oscillatoria is green due to the presence of chlorophyll a pigment. The chlorophyll pigment will absorb all other wavelengths in the light except green color. Hence, it appears in green color by reflecting green light. The presence of this green pigment will render Oscillatoria also green color. The other blue pigment present along with chlorophyll a is phycocyanin. These two pigments make this organism to appear as blue-green.


Ceramium species, like most red algae, contain the pigments chlorophyll a, phycocyanin, and phycoerythrin to capture sunlight. Phycocyanin and phycoerythrin are water-soluble phycobilin proteins that absorb strongly in the green, yellow, and orange light ranges. Chlorophyll a absorbs strongly in the red and blue-violet wavelengths. In addition, some intertidal Ceramium species have high concentrations of carotenoids, photoprotective pigments that prevent tissue damage during bright sunlight.