Quantum Chromodynamics
In the 1970s a quantum theory of strong interactions was developed called quantum chromodynamics (QCD). It includes a new gauge boson called the gluon.
The “charge” of the strong force is called color, and each quark comes in one of three colors: red, green or blue. The color force is transmitted by the gluon.
The observed hadrons are white, i.e.
they have all 3 colors, or a color and