  [abridged]We calculate multi-wavelength spectral energy distributions (SEDs)
(spanning optical to millimeter wavelengths) from simulations of major galaxy
mergers with black hole feedback which produce submillimeter bright galaxies
(SMGs), using a self-consistent three-dimensional radiative transfer code. We
reproduce correlations for local AGN observed in Spitzer Space Telescope's IRAC
bands, and make definitive predictions for infrared X-ray correlations that
should be testable by combining observations by Spitzer and the upcoming
Herschel mission with X-ray surveys. Our dynamical approach allows us to
directly correlate observed clustering in the data as seen in IRAC color-color
plots with the relative amount of time the system spends in a region of
color-color space. We also find that this clustering is positively correlated
with the stars dominating in their contribution to the total bolometric
luminosity. We present photo albums spanning the lifetime of SMGs, from their
infancy in the pre-merger phase to the final stage as an elliptical galaxy, as
seen in the observed $3.6 \micron$ and $450 \micron$ band to visually
illustrate some of the morphological differences between mergers of differing
orbital inclination and progenitor redshift. We find that SMGs are a broader
class of systems than starbursts or quasars. We introduce a simple, heuristic
classification scheme on the basis of the $L_{\rm IR}/L_{\rm x}$ ratios of
these galaxies, which may be interpreted qualitatively as an evolutionary
scheme, as these galaxies evolve in $L_{\rm IR}/L_{\rm x}$ while transiting
from the pre-merger stage, through the quasar phase, to a merger remnant.
