Green is the basic color of the plant world, even when we cannot see it. It is caused by the chemicals in chlorophyll, a word which means leaf green. The basic greens may be replaced by colors from other chemicals. But far more often, the basic greens are just hidden or masked by other colors. The rosy reds, blues and violets of the plant world may be caused by anthocyanin chemicals   a word which means flower blue. The oranges and yellows may be caused by carotinoids, a word borrowed from the carroty carrot.

The orange and yellows of the citrus plants come from carotinoid chemicals. The basic green chlorophyll of a lemon is masked by the same carotinoid chemicals which color the sunflower and the zinnia, the corn and the goldenrod.