  In this paper, we explore the possibility of constructing the quantum
chromodynamics of a massive color-octet vector field without introducing higher
structures like extended gauge symmetries, extra dimensions or scalar fields.
We show that gauge invariance is not enough to constraint the couplings.
Nevertheless the requirement of unitarity fixes the values of the coupling
constants, which otherwise would be arbitrary. Additionally, it opens a new
discrete symmetry which makes the coloron stable and avoid its resonant
production at a collider. On the other hand, a judicious definition of the
gauge fixing terms modifies the propagator of the massive field making it
well-behaved in the ultra-violet limit. The relation between our model and the
more general approach based on extended gauge symmetries is also discussed.
