Leaves are green because of the presence of chlorophyll. The chlorophyll helps the plant in absorbing the lights lights having red and blue wavelengths. It actually reflects the lights with green wavelength. The chlorophyll helps the plants in making food. I hope that this is the answer that has come to your help.
Each plant is made of many plant cells performing photosynthesis. Inside of each of these tiny plant cells are one to hundreds of small structures called chloroplasts.