It shouldn't case color shift unless it was on an Eastman stock or something fade-prone, in which case the colors being removed would be part of the base dissolving or decomposing.
Filmguard is cleaning out that scratch line - it has minor cleaning properties. Basically, when you see a black scratch, that is dirt in the hole. Each of the other colors are emulsion layers being exposed, until you get to the white/clear base color of the film!