Colour magnitude diagrams K_s vs. H − K_s of the target regions: the 50 km s⁻¹ cloud (panel a), the 20 km s⁻¹ cloud (b), the Brick cloud (c), Control 1 (d), Control 2 (e), and the bulge region (f). The red and orange points indicate the detected double feature for the RC. The solid violet line corresponds to the reddening line of RC stars at an 8.2 kpc distance following the extinction curve from Nogueras-Lara et al. (2020b). The dashed blue line shows the extinction curve from Minniti et al. (2020). The black, violet, and blue error bars correspond to the systematics of the data and the two extinction curves, respectively.