Z$_{\odot}$ from the faintest to the brightest galaxies, with a $g$-$r$ color scatter of $\sim$0.04-0.05 magnitudes [@Gallazzi06]. In this work, we fix the metallicity to Z$_{\odot}$, but we cannot exclude that metallicity variations contribute to the scatter. We test the effects of metallicity on the scatter in $U$-$V$ color in Appendix E, finding a weak and opposite trend for the color scatter due to metallicity variations with redshift. Given the observed scatter in Figure \[scatter\], it is unlikely that metallicity has a large effect on this work.

The age as defined in stellar populations models strongly depends on the choice of star formation history. To simplify, we assume an expontentially decaying star formation history with $\tau$=0.1 Gyr and $0<A_{V}<3$. Using the stellar population synthesis code FAST [@Kriek09] with the @Maraston05 models and a @Kroupa01 IMF, we fit for the age of these stellar populations given the above constraints. Given our assumptions, we effectively measure the relative ages (and dust) of the quiescent galaxies, fixing all other parameters.

![These panels contain the ages of quiescent galaxies (as derived from spectral synthesis models in §3.2) as a function of rest-frame $U$-$V$ color, in four redshift bins. The reddest and bluest $U$-$V$ quartiles 