RGB star selection. Decontaminated CMDs (in the present work) from Subaru Suprime-Cam photometry with spectroscopically confirmed members of Leo A (Kirby et al. 2017) are overlaid as cyan crosses. Panel a: I vs. V − I diagram with the selection box for RGB stars outlined in red. All RGB stars falling within an ellipse of a = 8′ are shown as black dots (N = 726). Panel b: I vs. Q_BVI diagram used to decontaminate the RGB sample of objects with unusual spectra. All the outliers (magenta dots; N = 63) lying outside of the two inclined lines were removed from the sample. Panel c: I vs. Hα − R diagram showing additionally removed objects with |Hα − R| > 0.05 (magenta dots; N = 15). Panel d: CMD of the decontaminated sample of RGB stars (black dots; N = 648) and removed from the RGB sample stars (magenta dots; N = 78).