Top panel: r′ versus B − V color − magnitude diagram of the stars in the CoRoT LRa01 star field. The dots mark the bright stars (r′ ≲ 15.2 mag), for which three-color CoRoT lightcurves are available. The open circles mark the fainter stars (r′ ≳ 15.2 mag) with monochromatic lightcurves only. Main-sequence stars cluster in the left part of the diagram, giant stars in the right part. Bottom panel: 2MASS J versus J − Ks color − magnitude diagram of the stars in the CoRoT LRa01 field. Again, main-sequence stars cluster in the left part of the diagram, giant stars in the right part.