Colour-magnitude diagrams for K_s vs. J − K_s, H vs. J − H, and K_s vs. H −K_s (D15 data). The red dashed parallelograms indicate the red clump, the red ellipse marks stars that belong to the asymptotic giant branch bump and the red square contains ascending giant branch and post-main sequence stars. The three black arrows indicate foreground stellar population probably tracing spiral arms.