The Chlorophyta are widespread in virtually any habitat on earth where there is light, including ice and snow and desert soils. Although they are called green algae, their colour varies from green through shades of yellow, purple, orange, red or even blackish. Most are, however, green though not all algae that are green are green algae. Over 10000 species of chlorophytes are known.

A unicellular green alga colours the snow red.	Halimeda a   green alga that is characteristic of tropical reefs and that is commonly green in colour as well as name.	Haematococcus a  green alga whose colour is often orange to red. These are resting stages.