I can get it to do every two lights. Make a vertical matrix model that is one string with the RGB nodes per string as the nodes you need.
In effect 1 set the effect to bars set the palette rep bar all the way to the right. set the 6 color selections to red, green, red, green, red, green. When I do that I get a two light red/green chase and the speed is adjustable with the speed bar.
If you click the highlight box and fiddle with the speed it makes an interesting chase sequence.
Rick S