Since the Sixties, Buren works "in situ", ie. he produces artworks specifically designed for a certain place and public.

He bases his installations and exhibitions on a “visual tool” (outil visuel) of disarming simplicity: a pattern - always the same - of vertical white stripes that are 8.7 cm wide and alternate with other colours, which has become his signature.

”The Coloured Weathervanes, work in situ, 2007, Trivero" frames the perimeter of the panoramic terraces of the Lanificio Zegna (wool mill) with a rainbow of 135 flags, fluctuating between green and blue in a recurring scheme of seven Pantone shades.

By an optical effect, they seem to merge into a single colour that varies according to the light. It's a “full dressing” that performs the simple task of indicating the direction of the wind and recording the change in the seasons, as well as transforming an architecture that is deeply familiar to all the town's inhabitants.