Those fonts on mac D: (or linux?)
Anywho- that area of XGUI uses default
ULib supported arguments- Player(s), Number, Bool, and String are the main ones. Unfortunately, ULX does not support a ColorArg, so there's not any easy way to have one show up there on the cmds tab in XGUI.
That does sound like a potentially useful argument type, though. We may consider it in the future if time allows.