Encompassing the entire gallery floor at 22 Old Bond Street, the larger-than-life ‘Blue and Yellow Among Reds’ (1964) hovers above the viewer, consuming the space with a spirited performance of vibrant red, blue, yellow, black, and white. The carefully selected colour scheme features predominantly bright red circular elements, including two large vertical circles framing the entire mobile and a scattering of four suspended circles drifting in the centre of the work. There is a tier of one white and three black elements, and the remaining two pieces accent the palette, as noted in the title, with sky blue and golden yellow. The circular elements slowly dance from the ceiling, the connecting wires twisting under and over each other while retaining a soft sense of balance. By working with primary colours as well as the non-colours of black and white in a not quite symmetrical balance, Calder creates points of references to trace the movement of the mobile and emphasises the formal elements of physicality and aesthetics in the structure.