The image is a diagram depicting two cubes, each representing a color space. The diagram appears to be from an older scientific or technical publication, given its style and the aged paper background. **Left Cube:** * It's labeled with axes: 'R.r' (Red axis), 'C.yo' (Blue axis), and a 'Null' axis. * The cube is divided into sections with colors and labels: * 'Pink' (top face) * 'Red' (front face) * 'Purple' (side face) * 'Light purple' (top-side intersection) * 'Light blue' (bottom-side intersection) * 'Blue' (bottom face) * 'White hidden' (bottom-front intersection) **Right Cube:** * It's labeled with axes: 'Red direction', 'C.yI', and 'Blue direction'. * The cube is divided into sections with colors and labels: * 'Ochre' (top face) * 'Orange' (front face) * 'Brown' (side face) * 'Light brown' (top-side intersection) * 'Light green' (bottom-side intersection) * 'Green' (bottom face) * 'Light yellow hidden' (bottom-front intersection) **Overall:** * The cubes are positioned side-by-side. * There's text labeling the axes and colors within each cube. * The diagram is titled 'Fig. 112' at the bottom. * The background is a yellowish, aged paper color.