3-D advice blue communicating communication conditional conditions eye-catching glassy indication information informative informing insiders limited-access liquidy no-public-access notification notifying plastic prohibition raised restriction security semi-transparent sign signs staff staff-only warning words workers abstract angled angles appearance background bricks color colorful colour colourful concrete Designs detailed detailing distinctive footpath grooves ground level light path pattern patterned patterns pavement pavers paving paving-bricks rough shaped shapes smooth stones stonework surface surfaces textured textures