2D illustration of the difference between EvCon simulations and those based on single-age SED templates. All panels cover an observers-frame wavelength range from 912 Å to 2.6 μm for a redshift 0≤z≤3 (from bottom to top). The SEDs, displayed in a logarithmic representation, take only bandpass shift and wavelength stretching into account and are normalized to the flux density at ∼5500 Å of the SED at z = 0 (bottom line in each panel) to ease a comparison. Labels at the upper abscissa mark the central wavelength λ_c of the U, B, V, R, I, J, H, and K filters. a) EvCon simulation that uses a grid of (42) purely stellar SEDs covering an age between 2.2 Gyr (z = 3; upper row) and 13.7 Gyr (z = 0; lower row) for the contSF model and a stellar metallicity of Z_⊙/5. b) Simulation based on a 4 Gyr old SED that is simulated out to z = 3 in increments of 0.05. c) As in panel b for a SED corresponding to an age of 13.7 Gyr. Panels d-f follow the same layout yet refer to an exponentially decreasing SFR with an e-folding time τ = 1 Gyr that started 13.7 Gyr ago and additionally include nebular emission. The blank area at the upper-left is due to the reprocessing of the LyC radiation (< 912 Å) into nebular and dust emission.