What color of glass-reflecting pane do you install to preserve the maximum photosynthesis?
Chlorophyll, the main photosynthetic pigment in plants, looks green to us because it doesn’t absorb green — it reflects green. Green is of no use in photosynthesis, which uses the violet-blue and red-orange parts of the spectrum, but doesn’t use much green, yellow, or orange. So if you want to use color filters with a white light source, it helps to filter out green, yellow, & orange. So you could pass light through a roughly magenta-colored pane, which would transmit red and blue. The pane would cast a greenish reflection, just as plants do. If reflection is required, then use a green filter as a mirror, which will reflect white as magenta.
