abstract appearance architectural architecture background basic brick brick-wall bricks color colored colors colour coloured colours exterior external rough smooth solid standard strength surface surfaces texture textured textures uneven variation varied various wall wallpaper barrier brickwork building cement firm mortar perspective perspectives secure security traditional-brick-wall brickwall concrete holland masonry material Netherlands stone stones beige cobblestone desktop limestone pastel rectangles rectangular relief rock stone wall structure lines mosaic pavement merge modern walls brick wall backgrounds