Color deconfinement and subhadronic matter: phase states and the role of constituent quarks

Major aspects of the subhadronic state of nuclear matter populated with the unleashed color particles are reviewed. At high nuclear collision energies, this is expected to be a flash of quark-gluon plasma. Emphasis is put on the self-consistency requirement which must be imposed on any phenomenological description of the evolution of hot and dense nuclear medium as it expands (cools down) to the point where the final scattering away of secondary particles starts. The view is analyzed that in this process massive constituent quarks should play a major role at certain cooling stage. It is shown an inherently consistent explanation of data on the mid-rapidity yield of various kinds of hadrons and on direct dilepton production in high-energy nuclei collisions