on small, accurate spectroscopic samples that are biased due to the methods of selection, or large photometric samples limited by the accuracy of the photometric redshifts and depth of the survey. To address the problems associated with each method, the NEWFIRM Medium-Band Survey [NMBS, @vanDokkum09a] was designed to improve the photometric redshift accuracies while maintaining a large sample of galaxies. For the first time, we are able to determine the color scatter of galaxies on the red sequence for a complete, mass-selected sample with accurate photometric redshifts.

In this paper, we study the properties of a mass-selected sample of galaxies from the NMBS over four redshift intervals, focusing on the properties of the quiescent galaxies residing on the red sequence. Here, we will use the term “quiescent” to signify old stellar populations with red rest-frame colors ($U$-$V\!\gtrsim$1.4) that are not vigorously forming stars. Following @Brammer09, we correct the rest-frame $U$-$V$ colors for dust reddening allowing a clean separation of the red and blue sequences. As expected, the star formation rates of these “quiescent” galaxies from SED modeling are typically low (the median SFR is 0.2 M$_{\odot}$ yr$^{-1}$), although some probably have ongoing star formation up to the level of $\sim$10 