RGB color model
An additive color model mixing red, green, and blue light.
RGB is an additive color model in which red, green, and blue light are combined in varying intensities to produce a wide range of colors. Each channel is typically an integer from 0 to 255 (or 0–100%), and all three at full intensity make white, while all at zero make black. RGB is how screens emit color, and its values are often written in hexadecimal for the web (e.g. #1f6feb).
Example: rgb(255, 0, 0) is pure red; rgb(31, 111, 235) is the hex color #1f6feb.