When you say (for example) "level 4 do this" "(still) level 4 do that" ... "level 3 do this" ... "(still) level 4 do that" I find that last "still" confusing. It should be "(back to) level 4" or some such thing.
But I have a deeper question about this whole approach. I guess some people do learn to understand recursion by tracing the code, but I find with students that that doesn't help them write their own recursive programs to do something different. For that, you have to learn to take on faith that the recursive call will do what it claims to do, and see how that fits into the current level. So my idea of a pedagogic tree project would be this:
https://snap.berkeley.edu/snap/snap.html#present:Username=bh&ProjectName=color%20tree