Top row: marginal posterior probability densities of the slopes (in units of mag (103 km s−1)−1)) of the LINEAR intrinsic color–velocity model applied to the data. Each posterior density is normalized to integrate to one so that more precise, narrow posterior pdfs are taller. The vertical lines indicate zero slope. We also indicate the posterior probability in the right tail ptail = P(b > 0). The slopes of the intrinsic B − V and B − R colors vs. velocity are most significantly different from zero. The slope of intrinsic B − I color vs. velocity is not statistically significant. Bottom row: marginal posterior probability of the mean intrinsic color difference between HV and NV SNe Ia, Δθ = θHV − θNV (in units of mag), under the STEP intrinsic color–velocity model applied to the data. The vertical lines indicate zero intrinsic color offset. We also indicate the posterior probability in the left tail ptail = P(Δθ < 0). The intrinsic color offsets are most significant in B − V and B − R, whereas the offset in B − I is marginal.