This chapter dwells on the colour chart as technology of organization. Following Benjamin’s distinction between medium of perception and technical apparatus, the colour chart is discussed as a materialization of colour’s organizational forces. For one, the colour chart disciplines the unruly, unstable, and treacherous realm of colour into orderly, manageable, and commercially exploitable colours. Then, by way of manifold forms of charts and grids, colour becomes a technology of organizing the social. However, colour is a perennial force of disorganization. The history of the colour chart is thus also one of grappling with colour’s volatility and unruliness.