Chlorophyll preferentially absorbs red and blue light, and carotenoid pigments (which produce the vibrant reds and yellows of fall foliage) pick up a slightly different shade of blue.

• 叶绿素善于吸收红光和蓝光，类胡萝卜素（让落叶呈现鲜红与鲜黄的色素）则吸收稍微深一点的蓝光。