Hello Dear,

The three classification of algae is given below:

Chlorophyceae – These are called green algae, due to the presence of pigments chlorophyll a and b. Examples are Chlamydomonas, Spirogyra, and Chara

Phaeophyceae – Also called as brown algae, they are predominantly marine. They have chlorophyll a, c, carotenoids and xanthophyll pigments. Examples are Dictyota, Laminaria, and Sargassum

Rhodophyceae – They are the red algae because of the presence of the red pigment, r-phycoerythrin. Examples are Porphyra, Gracilaria, and Gelidium.

Good Luck