Colour-magnitude diagrams H vs. J − H of (upper panels), and K_s vs. H − K_s (lower panels) for the central region of the GALACTICNUCLEUS survey (left panels), and the NSD East (right panels). The blue dashed parallelograms indicate the stars considered to compute the slope of the RC features. White dots depict the solutions obtained when applying the GMM method and their associated uncertainties.