Can't see range text in FCS tests

It's difficult to analyze the tree node sources in the tests:

<img width="791" alt="Image" src="https://github.com/user-attachments/assets/26dfd0e8-ce03-4333-bec4-f19147afae59" />


A possible fix and other options suggestions have been discussed in #13403.