The first thing you refer to is known as the generations
of particles. One of the mysteries of particle physics is why there are three almost identical generations of particles.
In fact there are 8 gluons, not 6. Each gluon carries both a color and an anticolor, so they come in varieties like red-antigreen or blue-antired. Since there are three colors you might expect there to be 3x3 = 9 gluons, but for group theoretical reasons one of these 9 doesn't exist, so there are 8 gluons.
The fact that every particle has an antiparticle is well understood as one of the several nontrivial consequences of combining special relativity and quantum mechanics to get quantum field theory, which is the basis for all particle physics.