Evolution (from z = 0.5 to z = 0.1) of spectral energy distribution of a sample of 100 electron tracers initially located in the most magnetised regions of jets in the Run2 model, for several combinations of re-acceleration scenarios (see labels). The initial particle spectrum is given by the solid black line and the evolution of spectra (equally spaced every ≈0.5 Gyr) goes from the most to the least transparent lines.