so i worked on my 710 last night with some kydex and i was using a small torch to heat the kydex and i used a bic lighter to finish the fit. but it looks like there is some weird discoloration on my blade allmost like heat (temper) on the edge.. but i dont see how that is possible since the knife is closed? also a friend has a knife with a similar line that they bought NIB all along the edge that is a sort of greasy brown color (again similar to a temper line but not quite) has anyone else experienced this? or know what it is?