Age vs. UV − J diagrams of our cluster and moving group sample. Symbols are the same as in Figure  7. The left panel only shows stars with J + 17.29( J − K) < 13.87, where our FUV observations were complete. In the left panel, red points have J − K > 0.3, green points have 0.2 < J − K < 0.3, and blue points have J − K < 0.2. In the right panel, red points have J − K > 0.8, green points have 0.6 < J − K < 0.8, and blue points have J − K < 0.6. The main difference between these figures and Figure  8 is that we plot Equation (10), which gives the average age at fixed NUV − J rather than the average NUV − J at fixed age. While UV-bright stars do tend to be older than UV-faint stars on average, there is so much scatter at fixed age that the age of any individual star cannot be predicted well.