Here is how to hack
Engine\Content\EngineDebugMaterials\WireframeMaterial.uasset
to change the dark purple wireframe color of dynamic meshes:
The same logic can be daisy chained to change other colors too. The calculation is not super optimal but it works with the values the inbuilt color picker produces when hovering over something in a viewport.
It’s probably best to keep a copy of this asset as a backup in case the engine gets updated.