Automatic color harmonization

A computing device including a processor, memory, and a display, wherein the display is configured to represent a graphical user interface, and wherein the processor is configured to execute program instructions stored in the memory to perform operations comprising:

• obtaining a three-dimensional color model containing hue, lightness, and chroma dimensions, wherein the color model represents each of at least three thousand distinct colors as unique points within the hue, lightness, and chroma dimensions;
• displaying, by way of the user interface and in accordance with the color model, a rotatable three-dimensional representation of the unique points;
• receiving, by way of the user interface, a selection of a first point of the unique points and a selection of a second point of the unique points;
• and
• in response to receiving the selection of the first point and the selection of the second point, displaying, by way of the user interface and in accordance with the color model, a rotatable three-dimensional representation of the first point, the second point, a line connecting the first point and the second point, and a subset of the unique points that are within a particular radius of the line.