Wavelengths of Light That Are Most Effective for Photosynthesis

Plants have several types of pigments that allow them to absorb light for photosynthesis. Each pigment absorbs different wavelengths, so that the best wavelengths for plants depend on the type of pigment it has the most of.

...
Various plant pigments absorb different light wavelengths.

Chlorophyll A

Chlorophyll a, which is present in all photosynthetic organisms, absorbs blue light with wavelengths of 430 nanometers (nm) and red light of 662 nm. It reflects green light, so that the plants that contain it appear green. Compared to other pigments, chlorophyll a exists most abundantly in plants.

Chlorophyll B

Chlorophyll b, which is similar in structure to chlorophyll a, exists in green algae and plants. It absorbs light of 453 nm and 642 nm. Chlorophyll a helps plants absorb a more extensive range of light wavelengths.

Carotenoids

All organisms that conduct photosynthesis have carotenoids. They absorb green light between 460 nm and 550 nm best. Plants that contain mostly cartenoids appear red, orange or yellow.