Lefthand panel: g − r color (corrected only for the Galactic extinction) as a function of time since r_max for 14 SDSS SNe Ib/c. The average extinction-corrected ⟨ g − r ⟩ color of seven SE SNe (see Sect. 3.3.1 for details) is shown by a solid gray line. Its value at 10 days (this epoch is labeled by a vertical dashed gray line, where g − r = 0.64 ± 0.13 mag) is assumed as the intrinsic colour for computing the host extinction for each SN. A Cardelli et al. (1989) reddening law with R_V = 3.1 is adopted in the computation. Righthand panel: cumulative distribution functions of E(B − V)_host for SNe Ib, Ic, and Ic-BL. The corrections for SNe Ib and Ic-BL appear larger than those needed for SNe Ic. The uncertainty on each E(B − V)_host is 0.2 mag.