The strong force originates in a property known as colour. This property, which has no connection with colour in the visual sense of the word, is somewhat analogous to electric charge. Just as electric charge is the source of electromagnetism, or the electromagnetic force, so colour is the source of the strong force. Particles without colour, such as electrons and other leptons, do not “feel” the strong force; particles with colour, principally the quarks, do “feel” the strong force.
