Final answer:
We see a color when a surface does not absorb that specific wavelength of light, leading it to be reflected to our eyes. An object's perceived color is due to the wavelengths that its surface chemicals do not absorb. For instance, a red material reflects red and absorbs other visible wavelengths.
Step-by-step explanation:
When we see a color, it is the portion of the light spectrum that a surface fails to absorb. This is because objects that we see around us are light absorbers, meaning the chemicals on their surface will absorb certain frequencies of light and not others. The color we perceive is the light that is reflected rather than absorbed; for example, a red material absorbs all visible wavelengths except red, which is reflected to our eyes. Similarly, a gray object has the ability to absorb all parts of the spectrum equally, resulting in the gray appearance.
When all frequencies of light strike the eye simultaneously, we perceive white, and when no visible frequencies reach the eye, we perceive black. This interaction of light with materials explains why the same object might appear differently under sunlight compared to fluorescent light, which does not contain all the frequencies found in sunlight.