Average NCR distributions as a function of the wavelength, for every SN type. The distributions are built averaging the NCR values for every J-PLUS photometric filter from the bluer to the redder filter (left panel). The right plot is built as the left one, but using the continuum-subtracted filters and proportionally removing the number of zero NCR values in each distribution that correspond to the lowest fraction of zeros in a distribution in each filter, as described in Sect. 6.1.