Midnight Rainbow Dye

Strange Plants come back as a random dye, so you cannot ask for this one by name. It only enters the pool at all once the Martian invasion has been beaten, which means every plant you hand over before that point is incapable of producing it. Collect plants whenever you walk past one on the surface and turn them in as a batch.

It runs the color cycle in the opposite direction from the ordinary rainbow dye, which lands darker and cooler on most sprites. That suits heavy black or blue armor sets where a bright rainbow would flatten the detail out.