A proposal for T58090.
It's unreliable to mix 3D view and UI widget colors,
I've committed a change that uses text color, blending it with the background in the case both colors match.
This works with both blender light and dark theme colors.
We can always tweak the contrast (it might be a a little low at the moment)
Noticed this patch also changes color band, but it's using 3D view colors too.
Closing, other changes can be submitted as separate patches.