When a red filtered light is shown on a red flower, why does the leaves look black?

1 Answer
May 7, 2018

The flower is absorbing all wavelengths of light shone on it.

Explanation:

White light is actually a combination of every wavelength of visible light. When any object appears to be a certain color when introduced to white light, it is actually absorbing every wavelength of light except the color it appears to be. In this case, the flower is absorbing every wavelength of light except red. The red light that is not absorbed is instead reflected, so the red light is reflected into your eye and it appears red.

When red-filtered light hits this flower, the white light has no wavelengths of red light in it. As a result, the flower absorbs 100% of the light shone on it, reflecting no light and therefore appearing black (the "color" that results from the absence of light).