  The quantum entropy at finite temperatures is analyzed by using models for
colored quarks making up the physical states of the hadrons. We explicitly work
out some special models for the structure of the states of SU(2) and SU(3)
relating to the effects of the temperature on the quantum entropy. We show that
the entropy of the singlet states monotonically decreases meaning that the
mixing of these states continually diminishes with the temperature. It has been
found that the structure of the octet states is more complex so that it can be
best characterized by two parts. One part is very similar to that of the
singlet states. The other one reflects the existence of strong correlations
between two of the three color states. Furthermore, we work out the entropy for
the {\it classical} Ising and the {\it quantum} XY spin chains. In Ising model
the quantum (ground state) entropy does not directly enter into the canonical
partition function. It also does not depend on the number of spatial
dimensions, but only on the number of quantum states making up the ground
state. Whereas, the XY spin chain has a finite entropy at vanishing
temperature. The results from the spin models qualitatively analogous to our
models for the states of SU(2) and SU(3).
