Internal Color Properties of Resolved Spheroids in the DeepHubble Space TelescopeAdvanced Camera for Surveys Field of UGC 10214

(Abridged) We study the internal color properties of a morphologicallyselected sample of spheroidal galaxies taken from HST/ACS ERO program of UGC10214 (``The Tadpole''). By taking advantage of the unprecedented highresolution of the ACS in this very deep dataset we are able to characterizespheroids at sub-arcseconds scales. Using the V_606W and I_814W bands, weconstruct V-I color maps and extract color gradients for a sample of spheroidsat I_814W < 24 mag. We investigate the existence of a population ofmorphologically classified spheroids which show extreme variation in theirinternal color properties similar to the ones reported in the HDFs. These aredisplayed as blue cores and inverse color gradients with respect to thoseaccounted from metallicity variations. Following the same analysis we find asimilar fraction of early-type systems (~30%-40%) that show non-homologousinternal colors, suggestive of recent star formation activity. We present twostatistics to quantify the internal color variation in galaxies and for tracingblue cores, from which we estimate the fraction of non-homogeneous tohomogeneous internal colors as a function of redshift up to z<1.2. We find thatit can be described as about constant as a function of redshift, with a smallincrease with redshift for the fraction of spheroids that present strong colordispersions. The implications of a constant fraction at all redshifts suggeststhe existence of a relatively permanent population of evolving spheroids up toz~1. We discuss the implications of this in the context of spheroidalformation.