Buff is a light brownish yellow, ochreous colour, typical of buff leather. Buff is a mixture of yellow ochre and white: two parts of white lead and one part of yellow ochre produces a good buff, or white lead may be tinted with French ochre alone.
Buff (colour)
Standard buff after A. S. Jennings.
Buff after R. Ridgway.
Buff sand
A secondary color is a color made by mixing two primary colors of a given color model in even proportions. Combining two secondary colors in the same manner produces a tertiary color. Secondary colors are special in traditional color theory, but have no special meaning in color science.
Page from A New Practical Treatise on the Three Primitive Colours Assumed as a Perfect System of Rudimentary Information by Charles Hayter.