Damn!
Well, for the time being (and in v2.0 of the toolbar that I'm gonna post as soon as SWS adds a new command for coloring asymmetrical track/item selections to the same random color
), you can use regular commands in a custom macro, bypassing the need for a script:
* SWS: Set selected item(s) to custom color x
* SWS: Set selected track(s) to custom color x
And make 16 of those