RTF is a global modification that replaces all towns in the game.

And what about the color scheme? For these Nagas, the dark ones are the upgrade, and the light ones are the alt-upgrade; for the Kirin and the Toads, it's the opposite. It always seemed to me that the dark Nagas should be the alt-upgrade, i.e., the destructive aspect of Shalassa, as with all the other units.