The difference between RGB and RYB.

Question

I always remember learning that the three primary colors are Red, Yellow, and Blue. Many people rather insist that they are Red, Green, and Blue.

When you take paints or markers or something else along those lines, combing RYB will give you all the colors, whereas RGB will not. Furthermore, electronic displays and lights use RGB as their primary colors, not RYB.

So what exactly is the “true” set of primary colors. Or are there just two sets that function differently?

In: Technology

Answer 1

Colors are wavelengths of light. The human eye can see wavelengths from 380 nm (violet) to 700 nm (red). Other wavelengths aren’t visible to humans, but you can capture them with special cameras.

To distinguish between colors within that range of visible light, the human eye has cones that detect specific wavelengths more strongly than others. The cones are centered around the wavelengths of red, green, and blue.

So in a sense, the eye can only see red, green, and blue. When we see yellow light, what’s actually happening is that both the red and green cones in our eyes are equally stimulated.

If you mix red light and green light together, it looks the same as “actual yellow” to our eyes. It’s not ACTUALLY the same physically, but the human eye can’t tell it apart.

So that’s how TV screens (and computer screens and phone screens) work. They use a combination of red, green, and blue light to simulate every color the eye can see. They do NOT simulate every color in nature, but because our eyes only sense red, green, and blue, we can’t tell the difference.

So in that sense, the primary colors of light are red, green, and blue.

Paint is different. When you shine a light on colored paint, it’s absorbing some colors and reflecting others. When you mix two colors of paint, you get a mix of their absorbing and reflecting properties. It doesn’t work the same as light at all.

The proper red, yellow, and blue paints are good primary colors. You can make any color of the rainbow with just those three.

With ink, it works better to use cyan, magenta, and yellow as primary colors.