What color of light is most beneficial to improve the photosynthetic rate in greenhouse? Can visible light shine on the blue film, or just blue light?

If you fill the light, you usually use red light, blue-violet light or white light (white light is a waste of energy, because white light is generally more powerful, but only two color segments can be used)

Visible light on the blue film, only through blue light (what color through what light, the specific reasons related to physics, remember the junior high school teacher said, but forgot)

Therefore, greenhouses generally use colorless films to maximize the use of sunlight (if the film is red, there will be no blue light, and plant carotenoids will not be better utilized. Remember that the blue light region seems to promote starch synthesis)

Red light is mostly used to fill the light.