  We use long-run, high-resolution hydrodynamics simulations to compute the
multi-wavelength light curves (LCs) from thermal disk emission around accreting
equal-mass supermassive black hole (BH) binaries, with a focus on revealing
binary eccentricity. LCs are obtained by modeling the disk thermodynamics with
an adiabatic equation of state, a local blackbody cooling prescription, and
corrections to approximate the effects of radiation pressure. We find that
modulation of multi-band LCs on the orbital time scale are generally in-phase
(to within $\sim\,$2% of a binary orbital period), but they contain pulse
substructure in the time domain that is not necessarily reflected in BH
accretion rates $\dot M$. We thus predict that binary-hosting AGN will exhibit
highly correlated, in-phase, periodic brightness modulations in their
low-energy disk emission. However, detectability of these modulations in
multi-wavelength observing campaigns could be seriously compromised because
observed stochastic variability in AGNs typically has a higher amplitude than
our proposed signal. It is possible that observations over temporal baselines
of many binary periods may make the signal more prominent, but this would need
to be analyzed carefully. If jet emission is predicted by $\dot{M}$, then we
predict a weaker correlation with low-energy disk emission due to the differing
sub-peak structure. For the binary parameters we explore, we show that LC
variability due to hydrodynamics likely dominates Doppler brightening for all
equal-mass binaries with disk Mach numbers $\lesssim 20$. A promising signature
of eccentricity is weak or absent "lump" periodicity. We find hints that a
significant lag exists between $\dot{M}$ and low-energy disk emission for
circular binaries, but they are in-phase for eccentric binaries, which might
explain some "orphan" blazar flares with no $\gamma$-ray counterpart.
