Features:

Multi material assignment: (Do not change button colors after assingning the multimaterial. Do not assign multimaterial while in subobject mode.)

Change button colors:(Make sure to assign button colors before assigning multimaterial to the selected object )

Save and load gui presets: (Make sure to load the gui with corresponding button count )
Double click to change button color
Right click to change button text.
Single click to change materialID of selected polygon or element.
free version at:
http://www.scriptspot.com/3ds-max/scripts/color-id-for-polygons