  The IR divergences of supergravity amplitudes are less severe than those of
planar SYM amplitudes, and are comparable to those subleading-color SYM
amplitudes that are most subleading in the 1/N expansion, namely O(1/epsilon^L)
for L-loop amplitudes. We derive linear relations between one- and two-loop
four-point amplitudes and one-loop five-point amplitudes of N = 4, 5, and 6
supergravity and the most-subleading-color contributions of the analogous
amplitudes of N = 0, 1, and 2 SYM theory, extending earlier results for N = 8
supergravity amplitudes. Our work relies on linear relations between N >= 4
supergravity and planar SYM amplitudes that were recently derived using the
double-copy property of gravity, and color-kinematic duality of gauge theories.
