the three primary colors is usually called RGB why there is another instandard saying is RYB

The terms RGB and RYB refer to two different sets of primary colors, used in distinct contexts.

RGB (Red, Green, Blue) refers to the primary colors used in light-based systems like computer displays, televisions, and photography. When combined in various amounts, these three colors can produce a wide spectrum of other colors.

RYB (Red, Yellow, Blue) is called the traditional set of primary colors, often taught to children for painting and color mixing. These are the colors that cannot be mixed from other colors using standard art supplies; they are at the opposite ends of a color wheel and are the basis for mixing secondary colors. However, RYB is less accurate for describing how digital colors work because it doesn't fully explain the full spectrum of colors that can be created using light.

It's important to note that while RYB is easier to understand for artists mixing paints, RGB is more accurate for describing how digital images and displays work because it deals with additive colors (colors created by light) rather than subtractive colors (colors created by light absorbing pigments like paint).