Effect of SFHs on JK_s[3.6][4.5] and HK_s[3.6] color–color diagrams. Top panels: two SEDs of quiescent galaxies are shown in magenta SED and cyan, representing a population of 1 Gyr redshifted to z = 3 (i.e. z_form ≈ 6), and a population of 0.5 Gyr redshifted to z = 4 (i.e., again z_form ≈ 6), respectively. Bottom: color–color plots with evolutionary tracks for star-forming and passive galaxies. Tracks representing star-forming galaxies are shown in blue and cyan and their characteristics are shown in the inserted legends. Three tracks for quiescent galaxies are shown in magenta, orange and red: the magenta track is parametrized with an exponentially declining star formation with τ = 0.1 Gyr, orange track has τ = 0.3 Gyr, and red track has been parametrized with a delayed star formation history where τ = 0.1 Gyr.