Yes, we usually think of plants being green. It
sounds like you know that the green pigment
chlorophyll is important in photosynthesis. What
might be news is that there are actually many
pigments that can trap light for
If you live in a place where leaves change color
in the fall, you have seen some of the colors of
other pigments. Those leaves were green before.
Then the tree stopped putting chlorophyll into the
leaves, and the sunlight broke down the
chlorophyll that was there. The other pigments
were left behind. They were there all along, you
just couldn’t see them.
The different pigments use different colors of
light. You know the colors of the spectrum if you
have ever seen a rainbow. We can tell which colors
a plant is NOT using because those are the colors
being reflected to our eyes. They are absorbing
and using the other colors. So your average
plant, like corn, is reflecting the green light
and using the other colors. The purple cabbage is
using the green and other colors, and reflecting
Light at the purple end of the spectrum has more
energy than light at the red end. Why do you
think purple is not a very common plant color?
You might be interested in studying plant ecology
or plant physiology.
Thanks for asking,