Q:How RGB light works?
A:This is called additive color mixing. Colors of light add together in the eye. Mix green and red, you see a third color, yellow. Mix red and blue and you see purple. White is what you see when you mix equal amounts of all three. Additive color mixing is not a physical property of light, it is how the eye interprets light.
The ability to produce any color from mixing three primary colors are at the core of digital video and photography. Your eyes senses red green and blue (RGB), your camera sensor is a big array of RGB sensors, your computer screen is made up of RGB pixels. Here we are making digital lights with RGB emitters.