However, this number is only an estimate. Everyone perceives the world differently, so who’s to say how many colors there are exactly—the answer could vary depending on who you ask! There are 7 core colors in the world: red, orange, yellow, green, blue, indigo, and violet. Every other color is simply a variation of one or more of these colors. Scientists estimate that there are around 18 decillion varieties of each color. Red-green and yellow-blue refer to primary colors and their corresponding secondary colors. If you draw or read a color wheel, red is across from green and yellow is across from blue. [2] X Research source
Believe it or not, there may be a whole world of color humans cannot see. Your brain can only comprehend the colors you know (the core colors of the rainbow and their varieties). Who’s to know if animals see an entirely different world of color than what you’re familiar with.
There’s a tissue in the back of your eye called the retina. It’s this tissue’s job to spot light and let the brain know what it’s seeing. When light hits your retina, the tissue sends an electric signal to your optic nerve. The optic nerve’s signal travels through your brain’s thalamus (think of this like a post office), which then ships the signal to your visual cortex. It’s in the visual cortex where your brain starts piecing together the color, so you know exactly what you’re seeing. This may sound like a lengthy and time-consuming process, but it happens as quickly as it takes for you to look at something.
