Quarks contain color charge and obeying quantum chromodynamics rules they exerts strong binding elastic force.
They maintain 8 folds symmetry.8 Gluons play role in color charge transmission.Fractional electric charge must has some
value and bears some relation with color charge.If there is no
electric charge(+/-),what will happen?Probably most of electric charge
is transformed into color charge.Minute electric charge remained.

Quarks still confuse the life out of me.