Gaia DR3 YSOs on the 2MASS colour–colour diagram. The contour levels are at 5%, 25%, 45%, 65%, and 85% of the maximum density value. In the comparison with other catalogues, we use only the red contours of the DR3 distribution for better visibility of the underlying data points. The median, mean, standard deviation, and 5% and 95% quantiles of both colours are listed in Table 1.