Color Theory

Color Theory in the visual arts has three categories based on color wheel: primary color, secondary color, and tertiary color. Color theory began in the 18th century where the color theory how it originally started with three colors of Red, Yellow, Blue. There is difference in warm colors and cold colors. Warm colors are red, orange, and yellow. For cold colors are blue, violet, and green.

(Source)

https://en.wikipedia.org/wiki/Color_theory#Historical_background