Hematochrome is a yellow, orange, or (most commonly) red

biological pigment Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biol ...

present in some

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

, especially when exposed to intense light. It is a name used mainly in older literature. Hematochrome is a mixture of carotenoid pigments and their derivates.

References

Carotenoids {{biochem-stub