A test for possible correlations between interstellar reddening and the FUV-excess parameter, Q. Residuals are the absolute difference in Q, estimated by FUV and (B − V) colors from Equations (1) and (2), and a theoretical Q derived from the calibrated FUV–age relationship (Equations (4), (10), and (11)) Extinction values, A_G, were collected from the Gaia DR2 catalog.