How Do We See Colors?
The way we see colors isn’t very straightforward. The physics of color perception involves energy wavelengths, reflections and signals zapping back and forth in our brains. So what is color in science terms?
You may recall from elementary school that the rainbow follows a specific color pattern you might have learned as “ROYGBIV.” This pattern corresponds with energy wavelengths. Red has the longest wavelength, while violet has the shortest.
As sunlight — which is a combination of all wavelengths — hits an object, some materials will absorb specific wavelengths. The wavelengths that aren’t absorbed get reflected. This reflected light then reaches our eyes and makes us perceive the reflecting object as being a particular color.
How Does Your Eye Influence Color Perception?
The color-perception process doesn’t end when the light reaches your eyes. It involves the stimulation of rods and cones, which send a signal to the brain of what color we perceive. Cones and rods are activated by different types of colors and lighting scenarios.
Due to variations from person to person and differing environments, the perception of color can vary wildly. An object will look different in dim light versus bright light, and some people can have cones that don’t function normally, causing color-blindness. Even with properly working cones, your brain may interpret signals slightly differently from the person next to you.
Here’s how the entire process works.
- Light hits an object.
- Specific lightwaves reflect off some materials and get absorbed by others.
- That reflected light enters the eye, where the lens focuses it toward cones and rods.
- The cones and rods react to the light and encode it into signals that the brain can read.
- These signals get sent to the brain through a complex network of neurons and synapses. The brain then perceives those signals as color.
With all these moving parts, an object that’s reflecting specific wavelengths won’t always look the same between viewers, which is why finding unbiased color measurements is essential.
How Cones in Our Eyes Affect Our Vision
Those cones and rods are crucial to making sense of vision and light. Once light hits your eyes, the lens of your eye focuses it onto those light-sensitive cells, rods and cones, each of which picks up different wavelengths of energy. Rods work best in dim light, while cones are specialized for specific ranges of colors.
- L-cones: L-cones make up 64% of our cones and are also called red cones since they are sensitive to the longer wavelengths that make red light.
- M-cones: Making up 32% of cones in the eye, M-cones, or green cones, respond to medium-wavelength, or green, light.
- S-cones: S-cones are also called blue cones since they pick up shorter wavelengths like blue. They only make up about 2-7% of total cones.
- Rods: Rods work in low light and help us see at night with no color reception. They also play into our peripheral vision.
If you’re wondering what color humans see best, take a look at the M-cones. As it turns out, green is right in the middle of the spectrum and is the easiest color for us to see.
What Is Color Theory?
Color theory combines much of the information we know about color and turns it into a design tool. You’re probably familiar with the color wheel, which arranges visible colors by their natural electromagnetic wavelengths. For instance, the color wheel moves from red, the longest, to violet, the shortest.
There are several different ways to mix colors, such as additive and subtractive methods, but they usually work with primary colors, secondary colors and tertiary colors. Primary colors are those that can’t be created by mixing other colors. They are red, blue and yellow. You might notice that we don’t have a color receptor for yellow, but we have one for green. So how do we see yellow?
There’s a reason we associate yellow with sunlight and other bright lights. That’s because yellow is one of the brightest colors. To detect it, our brains combine the excitement levels of red and green cones.
