Scientific American has an excellent article about the color of plants in other worlds orbiting stars light years away from our solar system.
Have you ever imagined that the color of plants to be blue, red, orange, purple, black, and so on? I think that it's possible. It depends on the algae and the formation of plants under the ocean and what type of photons they need to absorb in order to spread.
The article is very long but worth reading. For further reading, click on the link below.
The Color of Plants on Other Worlds