Primitive colorization of three dimensional graphics to provide feedback to a developer

Encoded information is provided about how an image (51) is rendered. When the image (51) is initially rendered, preselected colors are used. The image (51) is re-rendered so that colors used to re-render the image (51) encode information about how the image (51) was originally rendered. For example, the colors for the re-rendered image (51) indicate for each part of the image (51), the number of vertices included in that part of the image (51). Alternatively, the colors for the re-rendered image (51) indicate for each part of the image (51), which type of primitive within a graphics library (22) is used to re-render the first part of the image (51), or the colors for the re-rendered image (51) indicate for each part of the image (51), scheduling path within the graphics library (22) used to render that part of the image (51).