An electronic device may include electrical components and other components mounted within an interior of a housing. The device may have a display on a front face of the device and may have a glass layer that forms a housing wall on a rear face of the device. The glass housing wall may be provided with regions having different appearances. The regions may be textured, may have coatings such as thin-film interference filter coatings formed from stacks of dielectric material having alternating indices of refraction, may have metal coating layers, and/or may have ink coating layers. Textured surfaces, cavities, coatings, and other decoration may be embedded in glass structures that are joined with chemical bonds at diffusion-bonding interfaces.