I am glad to be able to provide some input.
I think you might have neglected to remove highlighting from commas in the second set of examples (I acknowledge that this could be a file version issue).
The new example problem is exactly in line with what I suggested.
I'm not at all adamant about the two highlighting colors. I used separate colors for initial and for secondary highlighting mostly for the sake of our discussion, which has been fun.
Thank you!
–Kyle