To change the color of a node type:
An Node Colors dialog appears.
All nodes of the given type are immediately changed to the new color.
The color model used is RGB; a higher value for a color component adds more of that color. If necessary, pick other node types and change their colors.
Note: The windows display the new color scheme only as they are redrawn; you may need to explicitly refresh the windows to see the new colors (§).
This step is optional.
Note: You cannot change the color of a particular node; colors are tied to node types.