B − V color vs. rotation period P₁ of the 24 124 stars with at least one detected period (gray dots). The filled circles represent data from Baliunas et al. (1996, olive), Kiraga & Stepien (2007, purple), Irwin et al. (2011, red), and McQuillan et al. (2013, blue). Towards cooler stars we found an increase in rotation periods with a steep rise around B − V ≈ 0.6 supplying evidence of rotational braking. The black lines represent a color-period relation found by Barnes (2007) for different isochrones. The four stars mark the position of the Sun (blue), KIC 1995351 (cyan), KIC 1869783 (purple), and KIC 9580312 (red) for comparison.