W_RP − W_K index decomposed into its three contributing colors. The points with negative values on the horizontal axis represent the term −1.3 (G_BP − G_RP), the points between 0 and ≈2 on the horizontal axis represent the term +0.686 (J − K_s) while the points more positive than ≈2 represent the term G_RP − K_s. Different stellar groups are marked with different colors as indicated in the lower-left corner of the figure. See text for a detailed description.