Actually I think it is possible to apply con color to v0 lvl, just not directly. Since lvl is dynamic data, it doesn't mater if you nest it.
Insert a page object where level is now with a dynamicdata="/GameData.Target.Name" and filter for color only, then paste level into the new page.
The new parent page should apply the con color from Target.Name to anything inside it
Thought about doing this for my target windows, but decided to leave v0 with the default behavior. The target name does color, so con is there.
BTW /con still gives a text description of mob difficulty.