Mixed Olive may be compounded in several ways; directly, by uniting green and. purple, or by adding to blue a smaller proportion of yellow and red, or by breaking much blue with little orange. Cool black pigments, combined with yellow ochre, afford eligible olives. These hues are called green in landscape, and invisible green in mechanic painting. It is to be noted that, in producing these and other compound colours on the palette or canvass, those mixtures will most conduce to the harmony of the performance which are formed of pigments otherwise generally employed in the picture.