Paint the bathroom and bedroom with a single neutral color that dominates both rooms. For example, paint the walls in a beige or gray that extends to both rooms.
Choose an accent color for each room. The accent color should be a single color that stands out and draws your attention to various parts around the room. The accent color for each room should be related. For example, you may choose blue accents in the bathroom and green accents in the bedroom. Blue and green are analogous color pairs and will not clash.
Decorate the bathroom and bedroom with the chosen accent colors. This decor may take the form of curtains, towels, picture frames, knickknacks, blankets and vases.
Stand at various points in the master bedroom and look into the bathroom for clashing colors. Move accessories as necessary, so any clashing colors will not be visible from the bedroom.