Real Colour.

Can anyone help with trying to achieve real colour in Aperture? (eg on-screen the same as real life). I'm shooting Raw images with a Canon 40D but always get heated / warmed up colours after downloading, mainly browns and greens. I'm aware this is a perennial problem with digital colour but any suggestions will be gratefully received. Recently I've been using the grey point in the Curves adjustment, which is ok but only works well if there is a neutral grey in the photograph to select from. Thanks.