Top: radial velocity measurements without any color-effect correction (black points) and their Keplerian fit (dashed red line) during Run A. Vertical dashed lines show the times of mid-transit, first, and fourth contacts. Bottom: after the empirical color-effect correction, radial velocity measurements outside of the transit are well-adjusted to the Keplerian fit, improving the out-of transit dispersion from 1.92 m/s to 0.23 m/s.