'Foster's thinks grey is a colour' - an old jibe, but one which, perhaps, contained a grain of truth at a time when the work of the Foster office was heading towards refinement and attenuation at the expense of expressive drama. The results can be seen in a projects of the late 1980s and early 90s. By its nature, High-Tech architecture - the category in which Norman Foster's work used to be bracketed (to his irritation) - celebrated fine materials: steel and other metals, concrete and glass. The use of colour seemed an irrelevance.
Yet a glance at the remarkable book Norman Foster: 30 colours (v&k Publishing, price £45) shows that the image of Foster's work as colourless is a gross simplification at best. The book records Foster's predilections as a colourist over more than 25 years, up to the time that his office began to collaborate regularly with Per Arnoldi - whose influence finds fullest expression in some of the interiors at the Berlin Reichstag, soon to open. Green and yellow were used to strong effect at Willis Faber in the 1970s. Yellow was used at the Renault Centre, Swindon, because it was Renault's corporate colour, but, fortuitously, also matched the yellow of nearby buttercups. Grey, for Foster, is a colour, used at Stansted to intensify the effect of the sky which pervades the terminal. In the Reichstag, colour was initially used, in a pragmatic fashion, as a code to indicate the function of spaces within the building. Only the involvement of Arnoldi, plus the encouragement of the clients (and of ex-Chancellor Kohl in particular), produced the richly coloured spaces which will be one of the big surprises of the building when it opens.
There is nothing un-modern about colour, but Foster's architecture reflects a variety of influences. It is much more diverse than, for example, that of Richard Meier (who seems to accept at face value the 'white modern' image of the 1920s and 30s). In recent and forthcoming Foster projects, the question is not whether colour will be used, but how, where and what. As Paul Overy remarks in an interesting introductory essay 'colour is the 'human' element in Foster's architecture, but it is also the element of 'nature' as opposed to the 'culture' of materials and structure'. Foster's work refuses to stand still, and its increasingly expressive character, with mere refinement no longer a goal in itself, is an indication of its potential for growth and change.