Hess diagrams (first column), relative differences (second column) between the Hess diagrams of the models and the SDSS observations, and the χ² diagrams (last column). From top to bottom, we show the comparisons based on the parameter sets 1 to 4, respectively. The x- and y-axes correspond to the colour index and de-reddened apparent magnitude . The left column shows the stellar density using a colour coding from 0 to 100 stars per square degree per 1 mag and 0.1 colour mag on a logarithmic scale. The middle panels are the relative differences between data and models with a colour coding from −50% to  +50%. The right panels are the lnχ² distributions with a colour coding from −2 to  + 2. Note that the colour ranges in the middle and right panels cover much larger ranges than in Fig. 5 of Just et al. (2011). (A colour version is available on-line.)