On the left, the m_F814W vs. m_F475W − m_F814W CMD for stars in the cluster field. Saturated stars are colored gray. The solid and the dashed lines are the MS ridge line and the locus of equal-mass binaries, respectively. On the right, a zoom-in of the same CMD in the region highlighted by the box, i.e. where the MS broadening is most clearly visible (upper panel), the verticalized CMD (middle panel), and the color histogram distribution (lower panel) (see text).