  The color of galaxies is a fundamental property, easily measured, that
constrains models of galaxies and their evolution. Dust attenuation and star
formation history (SFH) are the dominant factors affecting the color of
galaxies. Here we explore the empirical relation between SFH, attenuation, and
color for a wide range of galaxies, including early types. These galaxies have
been observed by GALEX, SDSS, and Spitzer, allowing the construction of
measures of dust attenuation from the ratio of infrared (IR) to ultraviolet
(UV) flux and measures of SFH from the strength of the 4000A break. The
empirical relation between these three quantities is compared to models that
separately predict the effects of dust and SFH on color. This comparison
demonstrates the quantitative consistency of these simple models with the data
and hints at the power of multiwavelength data for constraining these models.
The UV color is a strong constraint; we find that a Milky Way extinction curve
is disfavored, and that the UV emission of galaxies with large 4000A break
strengths is likely to arise from evolved populations. We perform fits to the
relation between SFH, attenuation, and color. This relation links the
production of starlight and its absorption by dust to the subsequent reemission
of the absorbed light in the IR. Galaxy models that self-consistently treat
dust absorption and emission as well as stellar populations will need to
reproduce these fitted relations in the low-redshift universe.
