  The distribution of surface classes of resonant trans-Neptunian objects
(TNOs) provides constraints on the protoplanetesimal disk and giant planet
migration. To better understand the surfaces of TNOs, the Colours of the Outer
Solar System Origins Survey (Col-OSSOS) acquired multi-band photometry of 102
TNOs, and found that the surfaces of TNOs can be well described by two surface
classifications, BrightIR and FaintIR. These classifications both include
optically red members and are differentiated predominantly based on whether
their near-infrared spectral slope is similar to their optical spectral slope.
The vast majority of cold classical TNOs, with dynamically quiescent orbits,
have the FaintIR surface classification, and we infer that TNOs in other
dynamical classifications with FaintIR surfaces share a common origin with the
cold classical TNOs. Comparison between the resonant populations and the
possible parent populations of cold classical and dynamically excited TNOs
reveal that the 3:2 has minimal contributions from the FaintIR class, which
could be explained by the $\nu_8$ secular resonance clearing the region near
the 3:2 before any sweeping capture occurred. Conversely, the fraction of
FaintIR objects in the 4:3 resonance, 2:1 resonance, and the resonances within
the cold classical belt, suggest that the FaintIR surface formed in the
protoplanetary disk between 34.6 and 47 au, though the outer bound depends on
the degree of resonance sweeping during migration. The presence and absence of
the FaintIR surfaces in Neptune's resonances provides critical constraints for
the history of Neptune's migration, the evolution of the $\nu_8$, and the
surface class distribution in the initial planetesimal disk
