When the arts come to play together it is not right to allot colour to the painter, plasticity to the sculptor and space to the architect as if they were their specific domains. Colour, plasticity and space are characteristic of all three. It goes without saying that the spatial use of colour lies within the domain of architecture. Space is not a medium for the architect, but in the best case it is a result. The painter has to take care of colour in architecture no more than the architect has to take care of the tectonics of a painting.
Aldo Van Eyck, 1955