One defining feature of flowers that makes them attractive is their color. Pollinators can distinguish and seek out flowers because of their bright hues while humans find joy in looking at the colorful blooms. But where do flowers get their color?
Flowers usually get their colors from pigments or molecules that selectively absorb wavelengths of light while reflecting others. These reflected wavelengths are the colors that we see.
The most abundant pigment involved in the production of flower color is flavonoids, where anthocyanins and anthoxanthins come from. Flower colors from indigo to red are formed from anthocyanins while the yellows and whites come from anthoxanthins.
Dynamics also play a part in flower color. The intensity and hue of flavonoids in flowers are also affected by other factors such as acidity, temperature, and metabolic activity.
Another pigment that provides flowers with color is carotenoids. These are localized inside cell structures called plastids and produce rich, vibrant yellow and orange colors. Carotenoids also aid in photosynthesis and in protecting the plant cell from light damage.
Other pigments in flowers include tannin, which gives brown and black hues, betalains, and chlorophyll. Betalains produce a range of colors while chlorophyll is responsible for the green in flowers and plants.
But like birds, some flowers also owe their appearance to structural color. For instance, some white flowers are colorless but appear to be white due to air spaces interspersed within the petals. These spaces reflect visible wavelengths of light causing the petals to appear bright white.
Flowers get their color mainly from pigments and structure. Although it’s not completely understood, the bright colors continue to fascinate people and play a vital role in pollination.