Editing Color charge (section)

== Red, green, and blue ==
In quantum chromodynamics (QCD), a quark's color can take one of three values or charges: red, green, and blue. An antiquark can take one of three anticolors: called antired, antigreen, and antiblue (represented as cyan, magenta, and yellow, respectively). Gluons are mixtures of two colors, such as red and antigreen, which constitutes their color charge. QCD considers eight gluons of the possible nine color–anticolor combinations to be unique; see ''[[Gluon#Eight color states |eight gluon colors]]'' for an explanation.

All three colors mixed together, all three anticolors mixed together, or a combination of a color and its anticolor is "colorless" or "white" and has a net color charge of zero. Due to a property of the strong interaction called [[color confinement]], [[free particle]]s must have a color charge of zero. 

A [[baryon]] is composed of three quarks, which must be one each of red, green, and blue colors; likewise an antibaryon is composed of three antiquarks, one each of antired, antigreen and antiblue. A [[meson]] is made from one quark and one antiquark; the quark can be any color, and the antiquark has the matching anticolor.

The following illustrates the [[coupling constant]]s for color-charged particles:

<gallery>
Image:Quark_Colors_with_white.svg|The quark colors (red, green, blue) combine to be colorless
Image:Quark_Anticolors.svg|The quark anticolors (antired, antigreen, antiblue) also combine to be colorless
</gallery>

<gallery>
Image:QCD Intermediate 1.png|A hadron with 3 quarks (red, green, blue) before a color change
Image:QCD Intermediate 2.png|Blue quark emits a blue–antigreen gluon, becoming green
Image:QCD Intermediate 3.png|The first green quark has absorbed the blue–antigreen gluon and is now blue; color remains conserved
File:Neutron QCD Animation.gif|An animation of the interaction inside a neutron. The gluons are represented as circles with the color charge in the center and the anti-color charge on the outside.
</gallery>

=== Field lines from color charges ===
{{main|Field (physics)}}
Analogous to an [[electric field]] and electric charges, the strong force acting between color charges can be depicted using field lines. However, the color field lines do not arc outwards from one charge to another as much, because they are pulled together tightly by gluons (within 1 [[femtometre|fm]]).<ref>{{Citation|title=Quantum Physics of Atoms, Molecules, Solids, Nuclei and Particles|edition=2nd|author=R. Resnick, R. Eisberg|publisher=John Wiley & Sons|year=1985|page=[https://archive.org/details/quantumphysicsof00eisb/page/684 684]|isbn=978-0-471-87373-0|url=https://archive.org/details/quantumphysicsof00eisb/page/684}}</ref> This effect [[Color confinement|confines]] [[quark]]s within [[hadron]]s.

[[File:Qcd fields field (physics).svg|400px|center|thumb|Fields due to color charges of [[quark]]s ('''G''' is the [[gluon field strength tensor]]) in "colorless" combinations.<br/>''Top'': Color charge has "ternary neutral states" as well as binary neutrality (analogous to [[electric charge]]).<br/>''Bottom'': Quark/antiquark combinations.<ref>{{Citation|title=McGraw Hill Encyclopaedia of Physics|first1=C.B.|last1=Parker|edition=2nd|publisher=Mc Graw Hill|year=1994|isbn=978-0-07-051400-3|url=https://archive.org/details/mcgrawhillencycl1993park}}</ref><ref>{{Citation |author= M. Mansfield, C. O’Sullivan|title= Understanding Physics|edition= 4th |year= 2011|publisher= John Wiley & Sons|isbn=978-0-47-0746370}}</ref>]]