  Both physical and dynamical properties must be considered to constrain the
origins of the dynamically excited distant Solar System populations. We present
high-precision (g-r) colors for 25 small (Hr>5) dynamically excited
Trans-Neptunian Objects (TNOs) and centaurs acquired as part of the Colours of
the Outer Solar System Origins Survey (Col-OSSOS). We combine our dataset with
previously published measurements and consider a set of 229 colors of outer
Solar System objects on dynamically excited orbits. The overall color
distribution is bimodal and can be decomposed into two distinct classes, termed
`gray' and `red', that each has a normal color distribution. The two color
classes have different inclination distributions: red objects have lower
inclinations than the gray ones. This trend holds for all dynamically excited
TNO populations. Even in the worst-case scenario, biases in the discovery
surveys cannot account for this trend: it is intrinsic to the TNO population.
Considering that TNOs are the precursors of centaurs, and that their
inclinations are roughly preserved as they become centaurs, our finding solves
the conundrum of centaurs being the only outer Solar System population
identified so far to exhibit this property (Tegler et al. 2016). The different
orbital distributions of the gray and red dynamically excited TNOs provide
strong evidence that their colors are due to different formation locations in a
disk of planetesimals with a compositional gradient.
