Answer:
Plums have high concentrations of anthocyanin, which absorbs light between 500 nm and 600 nm but reflects blue-purple wavelengths.
Spinach leaves have a high concentration of chlorophylls, which absorb light of lower wavelengths but reflect green ones.
Explanation:
White light is a mixture of the visible spectrum of light. Whenever white light meets a pigment, some wavelengths are absorbed by the pigments while others are reflected. The reflected spectrum is perceived as color and determined to be the pigment color or the color of an object or organism.
The color that tissue or vegetal organ express will depend on the pigment concentration or the combination of many of them.
The green color is normal in most vegetable species. Chlorophyll is responsible for this coloration, present in almost every vegetable species. This pigment absorbs blue and red wavelengths. Blue wavelengths a between 420-470 nm. But they reflect spectrums of green wavelengths, meaning that the expressed color is green in different tones.
On the other hand, many fruits -blueberries, cherries, plums, or grapes- and flowers express a high concentration of anthocyanin, a pigment that reflects spectrums of red, blue, and purple wavelengths. This pigment absorbs light of 250, 370, and 500-600 nm. Yellow and orange wavelengths correspond to 500-600 nm.
Plums:
- Pigment → anthocyanin
- Absorbs → light between 500 nm and 600 nm → yellow-orange
- Reflects → light between 300 nm and 370 nm → blue-purple
- Color detection → purple
Spinach leaves:
- Pigment → chlorophylls
- Absorbs → light between 420-470 nm → blue
- Reflects → light between 470-530 nm aprox. → green
- Color detection → green
