Top panel: Phillips diagram of M_B (peak) and Δm₁₅(B) of the KSP Type Ia SNe (colored symbols; same as Figure 5), as annotated with arrows, compared to the Phillips relation (black dashed line; J. L. Prieto et al. 2006) and a sample of other Type Ia SNe (gray crosses; C. R. Burns et al. 2018). Bottom panel: residuals of M_B (peak) and Δm₁₅(B) of Type Ia SNe from the top panel after subtracting the Phillips relation. The three dashed covariance ellipses represent the 2σ ranges, which are obtained with the best-fit hierarchical Gaussian class-conditional model for the early-blue, early-red, and early-yellow populations shown with blue, red, and gold colors, respectively. The transparent, indigo, dotted–dashed covariance ellipse represents the combined distribution for early-red and early-blue events.