Here is what my bumblegum digitata before my tank redo. It is not happy right now since it is at the bottom of the tank and some pieces have been broken off.
@SeanMc do you want to pick up a frag from my tank and see if the yellow tip will stay? Maybe bring me a frag from yours and I'll see if the tip will turn yellow. I don't think it is the light.
I have a nice Oregon tort colony. I could cut you a piece once my tank settle down so you can compare them. It grows slow for sure. I don't think that is an Oregon tort.