As children, we often think of color in terms of crayons, but in reality, color is defined in a number of different ways, depending on the application. In our early experimentation, we learned that red, yellow, and blue combine to make other colors, but that didn't stop us from coveting the box of crayons or colored pencils with some astronomical number of colors to get brightly saturated colors of all shades.
When we think of color, we tend to think of it in terms of color that has been applied to something, rather than color that is generated by something. When we print images, this is exactly how color works—we apply the colors we want. When we look at images on a screen, however, what we see is colored light, which combines differently to generate those colors. Let's look at these two methods, as well as a few color models used by most software applications, including ArcGIS Pro.