those are usually red locktighted new out of the box since there is really no need to get in there... normally. Heat is sometimes needed to break the red locktight. When you reinstall it its your call, red/blue, both will work, I'd use red if you have it.
how are you planning on getting the stripped one out?
"Holding on to anger is like grasping a hot coal with the intent of throwing it at someone else; you are the one who gets burned." Buddha