If you are more interested in classic or modern styles, you should choose black, white and grey for you sliding doors. If you are more a fan of traditional styles, you should choose natural wood or neutral shady colors that look very good in many home spaces. You can also choose a vivid color for the inside frame to make your window look much more noticeable. You should choose a color that match your home vibe and personality. For example, if you are looking for an energetic vibe, go for bright colors.