Dear Student,
Plants are green in colour due to the presence of chlorophyll a green coloured pigment. Chlorophyll absorbs certain wavelengths of light within the visible light spectrum. But, Green light is not absorbed but reflected, making the plant appear green.
Human skin color can range from almost black to nearly colorless (appearing pinkish white due to the blood in the skin) in different people. In general, people with ancestors from sunny regions have darker skin than people with ancestors from regions with less sunlight.
Regards