Uncalibrated (dashed blue), as well as calibrated (continuous blue) red-sequence model for the colour index i − J. The blue shaded region shows the offset uncertainty due to the uncertainty on the retrieved mean colour value μ (yellow dashed line and shaded region) for MOO J0319−0025. The dotted magenta line shows the spectroscopic redshift from Gonzalez et al. (2019, vertical) and the corresponding i − J colour (horizontal).