How long does a particle keeps his quantum state? Assuming there is one particle in our world but all the fields we know today exist also. Because particles can interact with fields, I guess they can change there quantum state. how long can they be in the same quantum state? And how it depends on their charges (i mean how it depends if it has color or electric charge and so on)? Does it count as a “measurement” if this particles interact with the vacuum? 
 A: These questions are easy to understand when knowing the basics of Schrodinger's Equation, which is the fundamental differential equation describing quantum mechanics. 
$$i\frac{d}{dt} \psi = H \psi $$
The Hamiltonian (potential + kinetic energy) moves quantum states forward in time and dictates the time evolution of the state.

how long can they be in the same quantum state?
  Mathematically, a state in an eigenstate of a Hamiltonian will remain in that state forever. Preparing such a state is tricky because you need a forever-constant Hamiltonian for this to happen, but it is theoretically considered to be possible for a state to remain forever in the same quantum state. In field-theory there will be a probability that this particle will become something else due to the interactions between fields, but this typically only happens with nonzero probabilities at high energy (this is why we spin electrons really fast in particle accellerators) . 
Assuming there is one particle in our world but all the fields we know today exist also. Because particles can interact with fields, I guess they can change there quantum state.

Adding a (classical) "field" like light that interacts with the particle will cause the quantum state of the particle to feel a new potential-energy. This creates new "energy eigenstates" that the particle can exist in. The schrodinger equation can be solved for this new potential energy.

And how it depends on their charges (i mean how it depends if it has
  color or electric charge and so on)?

You would have to work this out for your particular case. For the easiest case, I recommend looking up rabi oscillations and how the quantum state of an electron changes when excited by light. 

Does it count as a “measurement” if this particles interact with the
  vacuum?

Even if the particle interacts with nonvacuum light it doesn't necessarily count as a measurement. A measurement is when both the measurer and the state are forced to be correlated with eachother (allowing the measurer to discern the state is based on the measurement). If the light isn't forcing this specific situation, then it isn't "measuring" anything - and thus you can easily have fields that address but do not "measure" the state to be observed. 
