  Deep near-infrared and optical imaging surveys in the field reveal a curious
population of galaxies that are infrared-bright (I-K>4), yet with relatively
blue optical colors (V-I<2). Their surface density, several per square
arcminute at K>20, is high enough that if placed at z>1 as our models suggest,
their space densities are about one-tenth of phi-*. The colors of these ``faint
red outlier galaxies'' (fROGs) may derive from exceedingly old underlying
stellar populations, a dust-embedded starburst or AGN, or a combination
thereof. Determining the nature of these fROGs, and their relation with the
I-K>6 ``extremely red objects,'' has implications for our understanding of the
processes that give rise to infrared-excess galaxies in general. We report on
an ongoing study of several targets with HST & Keck imaging and Keck/LRIS
multislit spectroscopy.
