Colour-magnitude diagram of And XXXVI (left) within 1r_h (blue points, 0.284 arcmin radius) and 2r_h (blue and black points, 0.568 arcmin). A clear RGB can be delineated. In red we overlay an old (12.5 Gyr) metal-poor ([Fe/H] = −2.5) PARSEC isochrone using the distance to M31 (776 kpc). The isochrone matches the RGB locus well. On the right we show the CMD of an equal-sized (2r_h) area near the overdensity, selected to represent our field contamination for visual reference (see text for details on field contamination determination).