color charge

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An intrinsic property of quarks and gluons that determines their strong force interactions with each other.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun physics In the Standard Model of particle physics, a property possessed by quarks, anti-quarks, and gluons that determine rules for how these particles may interact. There are three pairs of colors and anti-colors -- named red, green, and blue, and their corresponding anti-colors (e.g., anti-red). The terminology has nothing to do with visible color.