"If a planet were found in a system with two or more stars, there would potentially be multiple sources of energy available to drive photosynthesis," study lead author Jack O'Malley-James, of the University of St. Andrews in Scotland, said in a statement. "The temperature of a star determines its color and, hence, the color of light used for photosynthesis. Depending on the colors of their starlight, plants would evolve very differently."
Green not a given
Most plants on Earth are green because they enlist a biomolecule called chlorophyll to drive photosynthesis. Chlorophyll absorbs sunlight in the blue and red wavelengths most strongly, which makes sense; blue light is extremely energetic, and our sun throws off red light in great volumes.
Chlorophyll reflects sunlight around the green part of the electromagnetic spectrum, on the other hand, which is why leaves look green to us.
But there's no guarantee that plants on alien worlds would do things the same way. Alien shrubs might be orange or red, for example, depending on what wavelengths of light are available to them. [A Field Guide to Alien Planets]