Stellar populations in simulations and dSphs. Panel a: recent SFH of Sculptor predicted by simulations made in Paper III (black lines), while the orange line is a linear fit to the SFH. Based on the latter fitted SFH, we simulated a synthetic CMD shown as the green points in panel b. This synthetic CMD will be compared with Sculptor’s CMD (within r_ell = 1.1 deg) from the Dark Energy Survey (DES) in panels c, with its CHeB candidates (blue dots) superposed. In both panels, we define some regions for statistics: the red-dashed line for our CHeB selection condition; cyan polygons for the blue plume(BP) region; violet polygons for the upper main sequence (UMS) region; brown polygons for HB region that to be exclude when counting inside UMS. Panels d and e show the same content as in panel c but for Fornax and Carina, respectively, and the polygons are revised accordingly.