There are two kinds of primary colors:  those you get by combining light (these are called "additive") and those you get by mixing pigments (these are called "subtractive").  As many computer users know, the additive colors are red, green, and blue.  Traditionally, the subtractive colors were red, yellow, and blue.  But more technically, they are magenta, yellow, and cyan (a kind of blue).
what are the base colors?