Optical colors of the Chandra sources as reported by H00. All magnitudes in these plots are in the U_n, G, ℛ, and K_s filters as described in H00 and § 4.2. Dots show the entire H00 catalog, diamonds are hard‐band detections, and plus symbols are soft‐band detections. The star symbols mark the two X‐ray–detected M stars. All colors available in the H00 catalog are plotted in this figure to show all the possible permutations. Note that not all X‐ray sources in the current sample have measured colors and/or magnitudes in the H00 catalog.