12 color chart color proportion

Quick answer：

The 12-color chart, also known as the Munsell color chart, is a color reference tool used in art, design, and manufacturing. It divides colors into three dimensions: hue, value, and chroma. The color proportion on this chart refers to the specific mix of these dimensions to create a wide range of colors. Each color is represented by a small square, with the proportions of hue, value, and chroma indicated by the size of the square within the larger color chart. This chart is particularly useful in color theory and color matching.