This work is a striking example of how painting can be included in an environment. This integrated work of art is one hundred metres long and was put together using ordinary smooth ceramic tiles. It had to meet very strict requirements: inexpensive material that was easy to put in place, resistant and easy to clean. On the platform in the direction of the suburbs, the colours which are arranged in series enable passengers to identify the course of the movement, following a vertical plane or an oblique plane. On the platform in the direction of the city centre, there are five double squares distributed over the whole wall. “Carrelage Cinq” was designed in yellow, orange, red, brown and blue. From a very simple monochrome surface, from which the observer can easily observe the whole work, each of the five parts of the composition develop a greater visual and structural complexity and more lively mobility in terms of colour.