The names inspire a sense of science fiction. We begin by describing the particles themselves. We get around this by saying that quarks only exist in bound groups of two or three with a total integer electric charge. The mass of the top quark is not accurately known, since only a handful have been detected to date. The other strange thing about quarks is that they serve not only as charges for the electric force, but also as charges for the strong force which binds quarks and nucleons together.
Any quark can be any color.
We shall see below why we distinguish the left and right handed quarks as separate groups. Their masses are given as limits since making them exactly massless has profound consequences for the Standard Model. Therefore, we do not want to assume anything, even though the evidence for massless neutrinos is not bad. Note that there is one neutrino brother for each of the more massive leptons. We will see in the next section that they can exchange identities within those pairs.