Centaur B – R colors and orbital inclination angles, i. The horizontal lines represent the median i of the gray and red populations. Application of the Wilcoxon rank sum test gives a 99.3% confidence level that red Centaurs have a smaller i distribution than gray Centaurs. Notice that only four red Centaurs have i values above the median i of the gray Centaurs. We are confident that red Centaurs have a smaller inclination angle distribution than gray Centaurs.