On one particular day during my time in primary school, I was in art class1. This alien environment was in a basement, bathed in the strange smells of pastel chalks and powdered paint. But on this day we were not drawing: the teacher had asked us the very inane question of what are colours. "Red", said one, "blue", another, "green", "yellow", "white", "purple", "pink", "black", "turquoise" (ooh!), "brown"... The kid in class who was known for his excellent drawing skills was quiet, until we became quiet. "I think that they are all colours, except for white and black." "What rubbish," thought I. Then he explained that white is the composite of all primary colours (so a kind of super-colour), and black the absence of any colour. The teacher was pleased with this answer, and the discussion continued around primary and secondary colours2. Read more …