Between 1992 and 1994, Brian Clarke and architect Will Alsop collaborated on Le Grand Bleu, the headquarters and council chamber of the Département des Bouches-du-Rhône in Marseille, France. Clarke was responsible for the cladding and colouration of the building, conceived as a 'skin of art' and rendered entirely through a novel technique that he devised.

Clarke's 1,200-square-metre artwork covers the building’s façade in bands of ceramic glaze in bands of ceramic glaze across the whole of the west elevation. Conceived at various times as vermilion, and then green, the final colour is a distinct, Mediterranean ultramarine close to the colour devised by Yves Klein. At the time of its construction in 1994, the Hôtel du Département (nicknamed at its inauguration 'Le Grand Bleu' by President François Mitterrand) was the largest building constructed in Marseille during the 20th century, together with the Corbusier building on the Prado.

Shortlisted for the 1997 Stirling Prize, Le Grand Bleu is considered a major work of late 20th century architecture. The architectural model of the final proposal was exhibited at Alsop's solo show of the scheme at the Mayor Gallery in 1994, and later at the Tony Shafrazi Gallery in the exhibition Brian Clarke: Art in Architecture.