Plastid pigments include chlorophylls a and c, fucoxanthin, heteroxanthin, diatoxanthin, and diadinoxanthin.

It is found in diatoms, along with other carotenoids like fucoxanthin and beta-carotene.

Diatoms are referred to as golden-brown microalgae because of the color of their plastids and because the carotenoids mask chlorophyll-a and chlorophyll-c.[2] Diadinoxanthin is a xanthophyll.

Xanthophyll pigments are photoprotective pigments that help protect cells from harmful effects of too much light energy (light saturation).

Thus it is the inactive precursor of diatoxanthin, which is the active energy dissipator.