Color and vision

We see color through a complex physiological system that includes our eyes, nervous system, and brain. Our eyes respond to light waves and translate them into the sensation of sight. In human vision, light waves enter the eye through the pupil and reach the retina located at the back of the eye.This area is lined with light sensitive cells called rods and cones:

Rods function at a lower light level and are more sensitive to light and dark than to color. They provide us with an ability to see in dimly lit situations and at

Cones functioning at higher levels of light, cones are our color receptors. There are three kinds of cones, which are each sensitive to a different wavelength of light or color.

The sensitivity of each kind of cone roughly corresponds to each of the primary colors of light which are red, blue, and green. Combinations of these three receptors are stimulated by light waves to create the colors that we see.

Upon exposure to light, chemical changes occur in the rods and cones. This creates an electrical impulse, which travels along the optic nerve to the visual cortex of the brain. This part of the brain acts as a computer, decoding the data and interpreting this stimulus as color.

Nature of Color : The composition of light and color

Objects have no color of their own. Instead, the appearance of color only occurs when light waves strike the surface of an object. Depending on the molecular structure of the surface, certain wavelengths of color will be absorbed and the remaining wavelengths will be reflected to the
receptors in the eye. All of the colors we see are a result of this process. For example, blue objects absorb the entire wavelength except the blue ones which are reflected back to the eye. Black objects absorb all of the wavelengths and reflect none. While objects absorb no wavelength at all and instead reflect all to the wavelengths back to the eye.

Almost all of the color we see is reflected from a surface; the only exception is color seen from a direct light source, like a candle. The concept of color manifestation is very well explained as an analogy in the book color right from the start, by Hillary page. “light is invisible until it illuminates an object in its path. It is easy to conceive of this if you think of automobile headlights at night. Their light is nothing but blackness as it travels through darkness. It only illuminates when it falls on and is reflect3ed by objects such as road signs in its path.