Wallpaper and paint

You have a brush and you could use dye as the paint and only paint the inside of the block (the angle your looking a tiny it with) eg. I wanted the outside my house birch wood but the inside could be painted red and as for wallpaper you can change that for textures so if I had a wooden wall I could make the inside look like bricks but just a slightly different colour to not get confused with the original brick block and also change colour of it :3