I was excited when I found out about Murray Lancashire's colour constructor tool. Much, if not all, of my understanding of colour is based on a light based approach (additive mixing) and performing an initial render of three dimensional spheres based the local colour of the object before painting the complicated shape - a technique I learnt from Sam Nielson.
I wanted to understand more about the tool and about light in general by taking a photograph placing it in an entirely different lighting scenario.
I had taken this photograph a long time ago. It was chosen because I believe (perhaps erroneously!) that it wasn't too overexposed and taken in sufficiently neutral white light so that it would not obscure my estimation of the local colours of the dome or of the main building itself. Even if mistaken, the colour constructor tool should render spheres accurately based on my assumptions. It would just be a slightly inaccurate representation of the Tom Tower in Oxford!