I have a couple that look like that. I tried to clean them up with CLP but that didn't help. I think it's caused by sweat or lotion when someone handled the gun but didn't wipe it off before storing the gun away or putting it back on display. Just put some gun oil and wipe it off lightly (or use a silicon cloth). That should help hide the "discoloration".Just bought a nib p2000 .40 I love everything about it. But I noticed on the finish on the slide when I was looking at it under a bright light, there is what looks like discoloration all over the slide. But looking at it under normal light you cannot see any discoloration. Is this normal?