Did you check out the AATK toolkit?
Color Net Dx
Changes the color of the net in Dx and Expedition at the same time.Both tools need to be open to work.This script will run from Dx or Expedition.
There is a new feature completed that allows user to set net class directly within DxDesigenr or Expedition. The tool is called "iCES" and is avaialbe to all Expedition Enterprise users when we release EE7.9.3. It will allow users to view most cosntriants and edit many of them directly in the scheamtic or layout editors.