These plastids are of many colours other than green, i.e., red, yellow, orange. They are found in petals of flowers and fruits. Purple colour is due to anthocyanin pigments which are found dissolved in cell sap. This is found in flowers, beet root, young purple-red leaves etc.
Chromoplasts are of the following types :
1. Phaeoplasts : These plastids are present in brown algae, Diatoms and Dinoflagellates. Brown coloured pigment fucoxanthium is the main pigment, along with chlorophyll. However chlorophyll b is replaced by chlorophyll c.
2. Rhodoplasts : These plastids are found in red algae. The red pigment R-phycoerytherin and R-phycocyanin, are present along with chlorophyll ‘a’, however chlorophyll ‘b’ is replaced by chlorophyll ‘d’.
3. Chromatophores of Blue-green algae : These are found in Blue- green algae. They have C-phycocyanin, C-phycoerythrin and chlorophyll ‘a’.
4. Chromatophores of photosynthetic bacteria : These are found in purple and nonpurple photosynthetic bacteria. These bacteria have purple red carotenoid pigments. Special types of chlorophylls- bacteriochlorophyll and bacterioviridin are also found in these bacteria.