Quantum fields exist everywhere, even if there are no particles present. When the fields become excited (that is, they’re no longer in their lowest-energy state) then a particle is formed. Some particles, like protons and neutrons, are made of quarks and are held together by the strong nuclear force (one of the four fundamental forces of the universe, the other three being electromagnetism, weak nuclear, and gravity). Quarks, in turn, are made of gluons that provide the force for quarks to stay together. Quarks are cemented by exchanging gluons with one another. The strong force results from color charge which doesn’t actually have anything to do with color; it’s more akin to electric charge. Fundamental forces, like the strong nuclear force, have specific force carriers which are exchanged between particles that the force controls. So particles are kept together by forces and interactions with one another. It’s quite a lot to explain and it can get a bit tricky. I hope this helped and thanks for always reading and asking interesting questions, William!