  We consider the possibility of an enlarged QCD color group, SU(3+$N^\prime$)
spontaneously broken to SU(3)$_c\times$SU($N^\prime$) with extra vector-like
quarks transforming in the fundamental representation. When the heavy quarks
are integrated out below the PQ-breaking scale, they generate an axion coupling
which simultaneously solves the strong CP problem for both gauge groups.
However, the axion mass now receives a new nonperturbative contribution from
the SU($N^\prime$) confinement scale, which can be substantially larger than
the QCD scale. This can increase the axion mass to be at or above the
electroweak scale. This visible axion can then decay into gluons and photons
giving rise to observable signals at Run-II of the LHC. In particular, if the
mass is identified with the 750 GeV diphoton resonance then the new confinement
scale is $\sim$ TeV and the PQ-breaking scale is $\sim$ 10 TeV. This predicts
vector-like quarks and a PQ scalar resonance in the multi-TeV range, with the
possibility that dark matter is an SU($N^\prime$) baryon.
