Why is grass green and not blue, red or black? Three sciences will help us find an explanation: biology, chemistry and physics.

Biology:
If you look at grass under a microscope, you can see chloroplasts – pronounced particles that contain chlorophyll – this is a pigment that is found in all plants and gives them a green color. The word “chlorophyll” itself is translated from Greek – “green leaf”. Grass absorbs carbon dioxide and processes it when exposed to the sun. As a result, pure oxygen is released into the atmosphere.
In autumn, the grass turns yellow, dried leaves fall from the trees, this is exactly what all plants would be like if they did not have chlorophyll. The fact is that with the onset of autumn it becomes darker and cooler. Due to lack of sunlight, chlorophyll begins to break down, so plants gradually lose their green color.

Chemistry:
If chlorophyll colors grass, it remains unclear why the pigment itself is green. Scientists believe that the color of organic compounds depends on the metal content. Hemoglobin, for example, contains iron, which gives the blood its red color. Chlorophyll contains magnesium, so the pigment itself turns green and transmits this shade to plants. This assumption has not yet been fully studied. Scientists also found that when replacing magnesium with zinc, the chloroplasts in the grass still remain green.

Physics:
Sunlight is heterogeneous, it has 7 main shades: red, orange, yellow, green, blue, indigo and violet. Grass absorbs all colors of the spectrum; it only reflects green. This happens because plants do not need the green rays coming from the sun to carry out photosynthesis. In this case, chlorophyll receives red and violet rays. With their help, it produces energy and then transfers it to the plant cells. The human eye picks up the green color reflected from grass, which is why it appears green to us.