Some of the modern CFL actually put out daylight-balanced light. But many of them tend to fall short in terms of colour rendering. Not all FL have the same Colour Rendering Index- some good (like the FL's used in Kino Flo) and efficient, but many of the domestic lamps are not. The latter may put out the right sort of white, but the low CRI may cause certain colours to register poorly or off on film. For instance, bright red objects recording as red orange or mint greens as yellow. When this happens, post corrections will not just involve white balance, but others like selective channel saturation as well.