GROND light curve g′r′i′z′JHK_s of the afterglow of GRB 100418A. The best fit of the combined optical/NIR and X-ray data is a smooth broken power-law with host contribution shown in dash lines. The epochs used for the spectral analysis are highlighted with the vertical bars. The first two epochs highlighted in light red correspond to the energy injection phase. The last five epochs in orange correspond to the slow cooling regime, the earlier epochs to fast cooling (see Sect. 3.3.1). For the blue epochs joint GROND-XRT SEDs were produced (see Fig. 4 and Sect. 3.2.1). The green and orange epochs correspond to the SED analysis that includes radio data (Sect. 3.3).