Trinity of color, or, The law of chromatics, or, How to paint
Oliver M. Olds's 1892 treatise on color and painting technique, held by the University of Maryland, was written for painters and students learning to mix and apply color. The single picture is a folding-plate style diagram of compound linear perspective, with a cone of vision, plane of vision, and aerial points labelled in capitals on a cream page, useful to a designer wanting a clear geometric construction layout.
