Ratio of rest-frame UV flux in the inner and outer aperture, based on the HST/ACS F814W mosaic, as a function of rest-frame U−B color. Filled and empty circles show pBzKs below and above z = 1.5, respectively, using the same relative scale. The blue and red contours mark the distribution of BzK + UVJ-selected galaxies (see Sect. 4.2) in the full z = 1.5−2.5 range and at z < 1.5, respectively. The error bars in the upper right corner show the typical uncertainty on both quantities while the filled and empty bars show the rest-frame color distribution of low-S/N pBzKs at z < 1.5 and z> 1.5, respectively.