105.1
There are five colors in the _Magic_ game: white, blue, black, red, and green.
Historical Rules · Effective 1 April 2011
Read Section 105 continuously, or open any rule on its dedicated page.
Chapter 1 · Game Concepts
Section 105
7 rules
There are five colors in the _Magic_ game: white, blue, black, red, and green.
An object can be one or more of the five colors, or it can be no color at all. An object is the color or colors of the mana symbols in its mana cost, regardless of the color of its frame. See rule 202.2.
Effects may change an object's color or give a color to a colorless object. If an effect gives an object a new color, the new color replaces all previous colors the object had (unless the effect said the object became that color "in addition" to its other colors). Effects may also make a colored object become colorless.
If a player is asked to choose a color, he or she must choose one of the five colors. "Multicolored" is not a color. Neither is "colorless."