Period-luminosity diagrams of Gaia LPV candidates in the LMC (left) and SMC (right), including only stars classified as C-rich (with extreme C-rich stars noted x-C-AGB in the panels), and using different luminosity indicators. From top to bottom: K_s band and W_J, Ks index from 2MASS, W_BP, RP index from Gaia, and the bolometric magnitude computed as described in Appendix A. Lines in the top four panels are best fit to the P–L relations of C-rich LPVs from Soszynski et al. (2007).