What exactly is color?
When light rays enter into our eyes, they stimulate the cone cells by electromagnetic radiation and creates the sensation of color. Everything we see around us is due to the reflection of light. If a material does not reflect any light waves, we cannot see it. A green leaf reflects the green light wave.
White light consists of all colors. Every color of light has a different wavelength. Red has the longest, and Violet has the shortest wavelengths. Red, blue, and yellow are called the primary colors because they cannot be created by mixing other colors.