m814W versus (m395N−m814W) CMD for the 1Pe (black) and 2Pe (red) populations selected in the chromosome map of Fig. 7. The filled circles are the points used to define the fiducial lines, which themselves are shown by the solid lines. See text for details. The horizontal dotted lines indicate the m814W magnitudes at which the color difference between the 2Pe and 1Pe fiducial lines is determined.