[singlepic id=285 w=500 h=500 float=] The key to consistent color in digital portrait photography is setting a white balance for your images. Somewhat surprisingly, the best thing to set "white balance" with is a gray card. By including a gray card in a digital image, you have a reference point of a neutral color that can be used to balance the rest of the image. This is something our eyes do naturally by removing color casts and making white look white. Unfortunately, a digital camera's "brain" is not nearly as sophisticated as a humans and needs help. That is why a gray card is vital in many situations.
I'm lucky to have a girlfriend who puts up with me taking pictures of her all the time. :-D