Yellow is a primary colour in painting and additive colour mixing, meaning it cannot be made by combining two other colours. In subtractive colouring, however, yellow can be created by combining red and green.
Red, green, and blue are the fundamental hues in additive colouring, the technique utilised on computer and television screens. These three hues are rendered as tiny dots on screens. Certain hues, such as red and green, illuminate to form other colours in order for the spectator to perceive yellow. When all three hues are illuminated simultaneously, white is the result.