Goethe's Theory of Colours
Colour from a sensory perception point of view. The least scientific or technological one, very atmospheric and philosophical, through experiences worth telling. It's funny how light and darkness were hinted at and picked up by artists with their use of value (black, grey and white) and how Goethe anticipated the opponent process (red versus green, yellow versus blue) through coloured shadows. Documentaries this good are hard to find.