  We explore how the colour of any new TeV-scale resonances that decay into top
quark pairs can be identified by studying the dependence of the observed
cross-section on a central jet veto. To facilitate this study, colour octet
resonance production was implemented in Pythia8 and colour singlet resonance
production is simulated after minor modifications. We find that the colour of a
2 TeV resonance can be identified with 10/fb of data at a centre-of-mass energy
of 14 TeV for a wide range of couplings, but only if the uncertainty in the
theoretical prediction is dramatically reduced from its current level.
