The white balance can be set to "auto" mode, or you can make your own custom setting. Only use the "auto" white balance when you know that there is some white information in your scene. For "auto white balance" to work properly, the camera needs to see something white. It needs a white-neutral reference point to balance out any color cast.
All light sources have a color cast. Your camera's white balance functions are designed to correct this issue. Color cast can range from a red color all the way up to a cooler, colder blue color. If you choose the wrong white balance setting in your camera, your artwork will have an improper color cast.
Custom White Balance
Your owner's manual will show you how to set up a custom white balance setting. For a custom setting, you're the person who brings the neutral reference point into the scene. This allows the camera to remove all color cast from that neutral reference point. Then, you can begin shooting. A white piece of paper works really well for this. Just make sure you fill up the camera's frame as you shoot your white, neutral reference point.