The colour white (7) will always print as black from AutoCAD. Traditionally, the drawing background colour has always been black and therefore, black background = white paper and white objects = black ink.
Of course, you can change your model space background to white if you wish. In that case, all your "white" (colour 7) objects will appear black. This may be more logical for you if you are unused to AutoCAD although most users seem to prefer the black background - I know I do, it's much easier on the eye.