Dust color at 80°–100° scattering angle as a function of stellar luminosity. The letters next to the color bars are the letter identifiers for the targets in Table 1. Panels a and b suggest that dust particles scatter light more efficiently at shorter wavelengths for less luminous stars. Although the trend in panel c does not agree with the other two, it is marginal and likely impacted by smaller sample size and data reduction artifacts. The shaded areas are 1σ, 2σ, and 3σ confidence bands from bootstrapping fit. See Table A.2 for the color values.