Why Do We See Different Colors?

We perceive different colors because of the way our eyes and brain interpret light waves. Light is made up of electromagnetic waves, and different wavelengths correspond to different colors. Here’s how it works:

Light Waves and Wavelengths

Visible light is a small part of the electromagnetic spectrum. Each color has a specific wavelength, with red having the longest wavelength and violet the shortest.

The Eye's Structure

Our eyes have cells called photoreceptors, specifically rods and cones, located in the retina. Rods help us see in low light but don’t detect color. Cones are responsible for color vision and are sensitive to different wavelengths of light. There are three types of cones:
L-Cones: Sensitive to long wavelengths (red)

M-Cones: Sensitive to medium wavelengths (green)

S-Cones: Sensitive to short wavelengths (blue)

Color Perception 

When light enters the eye, it hits the cones. Each type of cone responds to certain wavelengths of light more strongly. The brain processes signals from these cones to produce the perception of color. For example, if both L-cones and M-cones are stimulated, we might perceive yellow.

Mixing Colors 

Colors can mix in different ways. Additive color mixing occurs when light of different colors is combined, like on screens, resulting in white when all colors are combined. Subtractive color mixing happens with pigments or dyes, where combining all colors typically results in black.

Color Blindness 

Some people have a deficiency in one or more types of cones, leading to color blindness, where they can’t distinguish between certain colors.

This complex interaction between light, the eye's photoreceptors, and the brain allows us to see the rich array of colors in the world around us.