Average SEDs of bulges and disks in real galaxies for the largest possible sample, i.e. all single-band and multi-band fits (excluding u-and z-band fits) that produced good fit results. The SEDs recovered using single-band fitting are shown as blue and red dashed lines, respectively, and the values recovered from multi-band fitting are shown as solid lines. Error bars in the middle panel indicate the scatter of the distributions. Bold error bars (offset to the left) are given for multi-band fits for bulge (red) and disks (blue), and thin lines (offset to the right) for single-band fits. The brightest galaxies at m_r < 17.5 (harbouring 307 bulges and 1308 disks) are shown in the top panel, 17.5 < m_r < 18.5 in the middle panel, and 18.5 < m_r < 19.5 in the bottom panel. For comparison, the dashed orange line shows the SED of a typical quiescent galaxy (M 89), and the dashed green line shows the SED of a typical star-forming, bulge-less galaxy (NGC 0337).