A simple Blender Add-on that lets you change the accent / selection color everywhere at once.
Variations of the accent color are automatically calculated.
New in v1.1 : Also Colorize Panels & Text Elements - All done in real-time now!
Additional colorization options are also available as toggles. Check their tool-tips, and try them out.
Note: Made for dark themes, but probably works just fine on light themes.
Website Update notes etc: Here!
Public feedback & discussion: Here!
keTAC is donation / tip-ware