  Flux tube solutions within non-Abelian SU(3) Proca theory with external
sources are obtained. It is shown that such tubes have a longitudinal
chromoelectric field possessing two components (nonlinear and gradient), as
well as a transverse chromomagnetic field whose force lines create concentric
circles with the center on the axis of the tube. The scenario of a possible
relationship between non-Abelian Proca theory and quantum chromodynamics is
considered. In such scenario: (a)~the components of color fields have different
behavior: those which are almost classical, and those which are purely quantum;
(b)~the second components create a gluon condensate that is a source of the
field for the almost classical components of the Proca field; (c)~Proca masses
may appear as a result of an approximate description of the gluon condensate;
(d)~the question of gauge invariance is considered. It is shown that the
results obtained are in good agreement with the results of lattice
calculations. We make an assumption that an approximate description of a flux
tube in quantum chromodynamics can be carried out using classical Proca
equations but with a mandatory account of a gluon condensate.
