The armor goes from glow to radioactive, then starts over.
My level 30 armor went as follows:
+1 Glow
+2 Radioactive
+3 Glow
+4 Radioactive
And then I broke the +4 trying to socket it. I felt really stupid.
Anyways.
Forget the new games, the old ones are fun.
Ah, Gunz, the land of ego.