  We construct all supergravity theories that can be obtained through
factorized orbifold projections of N=8 supergravity, exposing their double-copy
structure, and calculate their one-loop four-point scattering amplitudes. We
observe a unified structure in both matter and gravity amplitudes, and
demonstrate that the four-graviton amplitudes are insensitive to the precise
nature of the matter couplings. We show that these amplitudes are identical for
the two different realizations of N=4 supergravity with two vector multiplets,
and argue that this feature extends to all multiplicities and loop orders as
well as to higher dimensions. We also construct a selected set of
supergravities obtained through a non-factorized orbifold action. Furthermore
we calculate one-loop four-point amplitudes for all pure super-Yang-Mills
theories with less-than-maximal supersymmetry using the duality between color
and kinematics, finding here a unified expression that holds for all four gluon
amplitudes in the theories. We recover the related amplitudes of factorized
N<=4 supergravities employing the double-copy construction. We observe a
requirement that the four-point loop-level amplitudes have non-local integrand
representations, exhibiting a mild non-locality in the form of inverse powers
of the three external Mandelstam invariants. These are the first loop-level
color-kinematic-satisfying representations in reduced supersymmetry theories.
