To turn on or turn off curvature shading colors:
Choose Inspect tab→Analyze group→Curvature Shading→Show.
To define the curvature shading settings:
Choose Inspect tab→Analyze group→Curvature Shading Settings.
On the Curvature Shading Settings dialog box, set the options you want, then set the Show Curvature Shading option.
Tip:
To view curvature shading on a model you must also shade the active window using the Shaded or Shaded With Visible Edges commands.
You can use the Find in Model button on the Curvature Shading Settings dialog box to find the smallest radius in the model.