The base material for a pressure-sensitive adhesive tape or sheet of the present invention is a different-colored laminated base material having a layered structure in which a plurality of film layers having different colors are laminated adjacently, and is used as a base material in a pressure-sensitive adhesive tape or sheet having a base material and a pressure-sensitive adhesive layer disposed on at least one surface of the base material. The base material for a pressure-sensitive adhesive tape or sheet is capable of providing the pressure-sensitive adhesive tape or sheet with a light-reflective property and/or a light-shielding property without requiring the formation of an ink layer and with an excellent tear resistance.