I know this has been discussed here before (I read the thread somewhere...) but I've heard an LDI can turn pink if exposed to high humidity like in a bathroom while taking a hot shower and no ventilation.
I'd have to check the exact policy at work, but a pink LDI does not automatically exclude a device from a warranty exchange. Red does, but pink doesn't to my knowledge. But again, I'd have to check to be 100% sure since I've never had to deal with anyone who said it was pink.
Dave