The green colour in grass-and in most other plants-comes from chloroplast within the cells, each of which contains four different colours or pigments. These are: chlorophyll a, which is the strongest and is blue-green; chlorophyll b. which is yellow green; xanthophylls, which are yellow; and carotene, which is orange and gives carrots their bright colour.
Grass goes from light green in early spring to dark green and brown in summer and’ autumn because the amount of each pigment changes, like the paint on a palette, to mix new colours.
