Color–color diagrams (left panels) of the simulated subpopulations of white dwarfs with metal-rich progenitors (blue circles) and metal-poor progenitors (red circles), for two metallicites of the subpopulations, Z = 0.0 (top panel) and Z = 0.02 (bottom panel). In both cases we show the results for a fraction of the subpopulation f_Z = 0.3. The resulting white-dwarf luminosity functions (solid lines) are compared to the observational one (squares) in the right panels. See the online edition of the journal for a color version of this plot.