I have made changes for issue #7863 based on theme requirements.
I have attached screenshots showing how the updates look across all themes for your reference.
If the current color does not fit well with the theme or if you have any suggestions for improvements, please let me know.
Is the colour contrast high enough on the row numbers for selected rows in the high contrast theme? The black on grey seems like it might not be to me, but I haven't tested.
I wonder also if we should make the row numbers bold all the time. Thoughts?