C21 and C32 colors from Fig. 4 shown with lines indicating the loci for simple thermal models for the emission. The solid lines represent the colors predicted from a variety of Raymond‐Smith models, with each track representing a different metallicity: zero abundance, 10%, 20%, 50%, and 100% (left to right) of solar. Along a given track, each symbol represents a different temperature: 0.2, 0.4, 0.6, 0.8, 1.0, 1.5 keV (bottom to top).