It isn't a question of raw or not raw format - it is a very simple question of white balance. It is the equivilant of shooting with the wrong color temperature film, and gives you poor results that can be SOMEWHAT fixed but it takes way too much work especially if the picture is also slightly over exposed.
if you are using the on camera meter, you may find that it is easily tricked by the excessive amount of blacks or whites in an image. Get yourself an 18% grey card and set your exposure off of that, shoot a couple of test images, and adjust from there. Don't leave your camera in automatic mode, set it up manually and keep an eye on the results as you shoot.