  The distribution in color and absolute magnitude is presented for 55,158
galaxies taken from the Sloan Digital Sky Survey in the redshift range
$0.08<z<0.12$, as a function of galaxy number overdensity in a line-of-sight
cylinder of transverse radius $1 h^{-1} \mathrm{Mpc}$. In all environments,
bulge-dominated galaxies (defined to be those with radial profiles best fit
with large S\'ersic indices) form a narrow, well defined color--magnitude
relation. Although the most luminous galaxies reside preferentially in the
highest density regions, there is only a barely detectable variation in the
color (zero-point) or slope of the color--magnitude relation ($<0.02
\mathrm{mag}$ in $^{0.1}[g-r]$ or $[B-V]$). These results constrain variations
with environmental density in the ages or metallicities of typical
bulge-dominated galaxies to be under 20 percent.
