Always clearly labeled. 90% of the tubes you're going to come across in any place selling tractor stuff are either Lithium complex or Polyurea. Most brands will color them differently for easy identification. IIRC, Deere's Lithium is green and their Polyurea is red... but I might have that backwards.
Deere states in all of their literature that I've read, that their Lithium complex and polyurea are 100% compatible. Deere sells good lubricants, but they're not magic. Meaning, if they say their lithium and polyurea greases are compatible, then I'd suspect nearly
all non-specialized lithiums and polyureas are probably compatible.