When painting or using additive color mixing, yellow is considered a primary color, meaning that it cannot be created by mixing two other colors. However, in subtractive coloring, yellow can be made by mixing red and green.
In additive coloring, which is the method used on computer and television screens, the primary colors are red, green and blue. These three colors are produced as small dots across screens. Certain colors light up to form other colors, such as red and green, to make the viewer perceive yellow. When all three colors are lit up at once, the result is white.