  Color-octet scalars arise in various Grand Unification scenarios and also in
other models of new physics. They are also postulated for minimal flavour
violation. Purely phenomenological imprints of such scalars are therefore worth
looking at. Motivated by this, we perform a complete one-loop calculation of
the $H^+ \to W^+ Z (\g)$ decay in a two Higgs doublet model augmented by a
color-octet $SU(2)_L$ scalar doublet. The computation is conveniently
segregated into colorless and colored components. The color-octet part of the
amplitude, being scaled by the color-factor, provides an overall enhancement to
the form factors. Crucial constraints from perturbative unitarity, positivity
of the scalar potential, oblique parameters, Higgs signal strengths and direct
search of a charged Higgs and color-octet scalars are folded-in into the
analysis. Sensitivity of the loop-induced $H^+ \to W^+ Z (\g)$ vertex to other
model parameters is elucidated. Finally, the prospect of observing a
loop-induced $H^+ \to W^+ Z (\g)$ interaction at the future hadronic collisions
is also discussed.
