The laws of harmonious colouring : adapted to interior decorations, manufactures, and other useful purposes
A colour-harmony manual by David Ramsay Hay, published in London and Edinburgh in 1838, aimed at interior decorators and manufacturers. The four diagrams are diamond and triangle colour charts with named hues in each cell, showing how shades group into arrangements for practical use. A designer could take from them a systematic palette method, pairing each hue with its neighbours across the grid.
