  We present an analysis of survey observations targeting the leading L4
Jupiter Trojan cloud near opposition using the wide-field Suprime-Cam CCD
camera on the 8.2 m Subaru Telescope. The survey covered about 38 deg$^2$ of
sky and imaged 147 fields spread across a wide region of the L4 cloud. Each
field was imaged in both the $g'$ and the $i'$ band, allowing for the
measurement of $g-i$ color. We detected 557 Trojans in the observed fields,
ranging in absolute magnitude from $H=10.0$ to $H = 20.3$. We fit the total
magnitude distribution to a broken power law and show that the power-law slope
rolls over from $0.45\pm 0.05$ to $0.36^{+0.05}_{-0.09}$ at a break magnitude
of $H_{b}=14.93^{+0.73}_{-0.88}$. Combining the best-fit magnitude distribution
of faint objects from our survey with an analysis of the magnitude distribution
of bright objects listed in the Minor Planet Center catalog, we obtain the
absolute magnitude distribution of Trojans over the entire range from $H=7.2$
to $H=16.4$. We show that the $g-i$ color of Trojans decreases with increasing
magnitude. In the context of the less-red and red color populations, as
classified in Wong et al. 2014 using photometric and spectroscopic data, we
demonstrate that the observed trend in color for the faint Trojans is
consistent with the expected trend derived from extrapolation of the best-fit
color population magnitude distributions for bright catalogued Trojans. This
indicates a steady increase in the relative number of less-red objects with
decreasing size. Finally, we interpret our results using collisional modeling
and propose several hypotheses for the color evolution of the Jupiter Trojan
population.
