Each time colour decisions are made, I try to avoid taste and aim for luminosity, by that I mean the result of how the colours interact - or at least the ambition I have when deciding upon the colour. I consider surface as meaning that the whole thing needs to be active and end up working together. I am not suggesting a miasmic soup. Furthermore I don't think dealing with colour means you can't build space into the work. Space can happen through the colour, but it is surprising - when you try to control it, it tends to lead to tonality - a sort of predictable and predicted space. Colour can 'breathe' or it can look turgid and there's a whole range of degrees in between. You can set up systems and so forth and find ways to describe them, but I think its simpler - either the colour adds up to something greater than its parts or it doesn't.