Conditional probability density (Equation (A1)) of the deviation of a pair (n_C = 2) of apparent colors from the mean intrinsic colors for a given velocity v. The solid, dashed, and dotted contours enclose approximately 68%, 95%, and 99% of the 2D probability. For an average dust extinction of τ = 0.4 mag and σ_C = 0.05 mag (for both B − V and V − R), the dust reddening is dominant over the intrinsic color variance, leading to a sharp tail toward redder colors (red contours). For an average dust extinction of τ = 0.3 mag and σ_C = 0.1 mag, the effects of intrinsic variance and dust reddening are about equal, so the shape of the contours is more rounded and the dust reddened tail less pronounced (blue contours). The tilt of the dust reddened tail is set by the value of R_V, which is fixed to 3.1 here.