  We consider two fundamental long-standing problems in quantum chromodynamics
(QCD): the origin of color confinement and structure of a true vacuum and color
singlet quantum states. There is a common belief that resolution to these
problems needs a knowledge of a strict non-perturbative quantum Yang-Mills
theory and new ideas. Our principal idea in resolving these problems is that
structure of color confinement and color singlet quantum states must be
determined by a Weyl symmetry which is an intrinsic symmetry of the Yang-Mills
gauge theory, and by properties of a selected class of solutions satisfying
special requirements. Following this idea we construct for the first time a
space of color singlet one particle quantum states for primary gluons and
quarks and reveal the structure of color confinement in quantum Yang-Mills
theory. As an application we demonstrate formation of physical observables in a
pure QCD, pure glueballs.
