GyMac
US Veteran
I feel your pain and have had my share of bad experiences with touch-up blue. If it were just holster wear that would be one thing, but this sounds different and it would bother me, too. I have had some positive experience with Oxpho blue, but probably the best you can hope for is to make the spot less noticeable. If it were me, though, I would try Wonder Blue. They claim that it will only blue the exposed metal and not change the surrounding blue. If this is true, it will solve one of the big problems with cold blue which is that surrounding metal. If you try it, please let us know the results.