Top panels: the relative contribution of the various spectral components inferred with the DISKBB+SIMPL⊗DISKPBB model (corrected for absorption) for each epoch. The full model is shown in black, while the DISKBB contribution is shown in red, and the DISKPBB contribution (before modification by SIMPL) is shown in blue. In this case, the spectral evolution is dominated by the cooler of the two thermal components (represented by DISKBB). Bottom panels: the same as the top panels, but for the DISKBB+SIMPL⊗COMPTT model. Here, the DISKBB contribution is shown in red, and the COMPTT contribution (before modification by SIMPL) is shown in blue. In this case, the spectral evolution is dominated by the hotter of the two thermal components (represented by COMPTT).