i₇₇₅ − z₈₅₀ color of galaxies. Left: the expected i₇₇₅ − z₈₅₀ color of galaxies is shown as a function of redshift for 4 different ages. The different solid lines refer to (from top to bottom) 7 Gyr old (red line), 4 Gyr old (green line), 2 Gyr old (blue line), and 1 Gyr old (cyan line). The dashed line refers to a 2 Gyr old template obtained with the Maraston (2005) models. The color is always i₇₇₅ − z₈₅₀ < 0.8 (horizontal black line) for redshift z < 0.8, and it is always larger than 0.8 for z > 0.8, this independently of the age of the stellar population considered. Right: the i₇₇₅ − z₈₅₀ color distribution of the 467 galaxies brighter than z₈₅₀ < 24 falling within 1 Mpc from the cluster center is shown. The solid red line marks the mean color ⟨ i₇₇₅ − z₈₅₀ ⟩ = 1.1 ± 0.09 of the 5 ETGs cluster members spectroscopically identified by Stanford et al. (1997). The dashed lines represent ±1σ. A second peak is evident in the distribution at the mean color of the 5 ETGs.