Q: quad view colors

Hi all,

What section of the preferences is used for the quad view colors.
In particular, the color and width of the divide lines in between the viewports.
I find the thin gray line in-between the 4 views very hard to see, and would like it to be slightly thicker and darker.

Anything that can be done in prefs, or is this something that needs to be added to the list of requests at Blender devs?