UNDEB the title “Color for Efficiency”, Matt Denning and Arthur A. Brainerd have described experiments made in an American machine shop by re-painting the machines in pale colours (Product Engineering, Jan., 1942). Machines are usually painted black or battleship grey, and their surfaces thus have a low reflexion factor. There is often too little brightness of colour contrast between the work and parts of machines forming its background. If these parts are finished with light-coloured paint, contrast is improved, and the work made easier to see. Moreover, the illumination of the work itself may be improved by light reflected from machine surfaces. The whole machine may be painted a uniform colour, or a different, but also pale, colour can be used for parts not in close proximity to the work. The general brightness of a machine shop is enhanced by this treatment. Where high machines, such as heavy presses, are used, a high reflectivity of their superstructure means that more light is reflected to adjacent machines, and troublesome shadows may be avoided. The colours tested were ranked on the results of a work-time study and on opinions of machine operators and measurements of reflexion factors. Light buff proved best, then aluminium and light grey. Yellow was found to be tiring. In Great Britain, the advantages of painting machines a light colour were recognized by the Departmental Committee on Factory Lighting, which recommended this practice in its fifth report, published in 1940 ; recent trials here have proved very satisfactory.