Mob difficulty graphics
 

Does anyone know which UI file has these? Specifically, I'm looking for the up/down arrows, the circle that displays the level, and the graphics that appear on the sides of the mob name if it's heroic or epic. I think they're all in widgets02.dds, but I wanted to check - and I assume they're recoloured by the game, not in the files?

Is there an XML file for this?

Don't have access to the game/UI to check right now, but references to them might be in ImageStyles.xml. They might be at least partly referenced in proxyactor.xml since they're used by the overhead display, and probably the target/implied target window.

Easiest way to backtrace is to fire up UIBuilder, go to the target or implied target window and find the elements there and see what image or imagestyle is called.

Color wise I imagine they are recolored automatically in game, so only 1 base image for each and then the game handles the tinting, like it does with item icon backgrounds.