The colour strong force is the strong interaction between the three quarks that a proton or neutron is made of. It is called the colour strong force because, like the electromagnetic force, the strong force has charges. The electromagnetic force has only one type of charge, which can be either positive or negative (magnetic charges are just slow-moving electric charges), but the strong force has three types. These three types of charges are named after colours: red, blue, and green. They also have anti-colours: anti-red, anti-blue and anti-green. Like the electromagnetic force's positive and negative charges, different colours attract, and the same colours repel. Some particles that have colour charge are quarks and antiquarks. The type of quark is not related to that quark's colour charge at all. Quarks are one of the smallest particles currently known. They take up no space because they are points, and they are the only particles that we have not been able to break apart from other particles yet. This is because the nature of the strong force between particles is that it becomes stronger the further away the particles are. The force carrier of the strong force is called the gluon. Gluons also have colour charge. Both quarks and gluons have properties that make them unique from other particles, as described in the Standard Model.