One of the unsolved problems in physics is why has there never been measured a free quark or gluon, but only objects that are built out of them, like mesons and baryons. A possible reason for this is that nature only allows neutral (colourless) or white light particles to exist and, may also be the reason we do not observe particles that consist of 2 quarks, say, or 2 anti-quarks.

Recently Pentaquarks were discovered at CERN's LHC. I believe that they are, either, 1) a strongly-bound structure of 5 elementary particles, for example, a 4 quark and 1 anti-quark composite arrangement so that the overall colour charge is neutral (colourless) [for example, red, green, blue, green + anti-green] or 2) a more weakly-bound coupling of white light meson and white light baryon particles, for example, as shown below:

Pentaquark = Baryon[quark1, quark2, quark3] + Meson[quark, anti-quark]

= " [red, green, blue] + " [red, anti-red] (say)

= White Light + White Light

= White Light

The Pentaquark can also be pictured as a sequence of 5 consecutive 'Colour' Trigrams of the type shown in Chapter 4 - The Colour Octave, of my blog (see below). Sorry, I don't have the time to upload.

Furthermore, if we can envisage the Trigram as a pixel (or node) on a 3D Grid then each yin (=0) or yang (=1) line of the Trigram would denote one sub-pixel from a set of 3 consecutive sub-pixels, resulting in an arrangement of pixels not unlike those featured in the manufacture of TV screens and computer monitors.