  In 2018, Jewitt identified the "The Trojan Color Conundrum", namely that
Neptune's Trojan asteroids (NTs) had no ultra-red members, unlike the the
nearby Kuiper Belt. Since then, numerous ultra-red NTs have been discovered,
seemingly resolving this conundrum (Lin et al. 2019; Bolin et al.12 2023).
However, it is still unclear whether or not the Kuiper Belt has a color
distribution consistent with the NT population, as would be expected if it were
the source population. In this work, we present a new photometric survey of 15
out of 31 NTs. We utilized the Sloan g'r'i'z' filters on the IMACS f/4
instrument which is mounted on the 6.5m Baade telescope. In this survey, we
identify four NTs as being ultra-red using a Principal Component Analysis
(PCA). This result brings the ratio of red to ultra-red NTs to 7.75:1, more
consistent with the corresponding Trans-Neptunian Object (TNO) ratio of 4-11:1.
We also identify three targets as being blue (nearly Solar) in color. Such
objects may be C-type surfaces, but we see more of these blue NTs than has been
observed in the Kuiper Belt (Seccull et al. 2018). Finally, we show that there
are hints of a color-absolute magnitude (H) correlation, with larger H (smaller
sized, lower albedo) tending to be more red, but more data is needed to confirm
this result. The origin of such a correlation remains an open question which
will be addressed by future observations of the surface composition of these
targets and their rotational properties.
