I also just managed to beat floor 50.
I noticed that since I don't have any -enemy def rainbows, I went with the +dmg/+atk per turn rainbows I have.



Went fairly easily, though the trial run managed to beat it a turn faster, with a higher score.
Still, I won't complain about it. A win after trying out the third team combination is a good win after what I saw was being described here.