  We present an analysis of 109 moderate-luminosity (41.9 < Log L{0.5-8.0 keV}
< 43.7) AGN in the Extended Chandra Deep Field-South survey, which is drawn
from 5,549 galaxies from the COMBO-17 and GEMS surveys having 0.4 < z < 1.1.
These obscured or optically-weak AGN facilitate the study of their host
galaxies since the AGN provide an insubstantial amount of contamination to the
galaxy light. We find that the color distribution of AGN host galaxies is
highly dependent upon (1) the strong color-evolution of luminous (M_V < -20.7)
galaxies, and (2) the influence of ~10 Mpc scale structures. When excluding
galaxies within the redshift range 0.63 < z < 0.76, a regime dominated by
sources in large-scale structures at z=0.67 and z=0.73, we observe a bimodality
in the host galaxy colors. Galaxies hosting AGN at z > 0.8 preferentially have
bluer (rest-frame U-V < 0.7) colors than their z <~ 0.6 counterparts (many of
which fall along the red sequence). The fraction of galaxies hosting AGN peaks
in the ``green valley'' (0.5 < U-V < 1.0); this is primarily due to enhanced
AGN activity in the redshift interval 0.63 < z < 0.76. The AGN fraction in this
redshift and color interval is 12.8% (compared to its `field' value of 7.8%)
and reaches a maximum of 14.8% at U-V~0.8. We further find that blue,
bulge-dominated (Sersic index n>2.5) galaxies have the highest fraction of AGN
(21%) in our sample. We explore the scenario that the evolution of AGN hosts is
driven by galaxy mergers and illustrate that an accurate assessment requires a
larger area survey since only three hosts may be undergoing a merger with
timescales <1 Gyr following a starburst phase.
