Use a grey wall instead of a white one, and your automatic will give you a better exposure. (I hate automatic cameras, btw) This will also give an automatic developer an easier time adjusting for the print level. Those machines just don't like stark white, and try to make it a light flesh tone.
If things are coming out very yellow, probably those "halogen" lights are tungsten. You can get a filter for your lens that will adjust for that. If they are only a little yellow, I would suspect the developer.
Don't worry about the colors on your digital, that can be adjusted on your graphics program. Everyone's monitor is a little different anyway, so ideal color is impossible online. You just try to get close, and leave it at that.