Hmm, that strip is a bit wider than the trim I saw in red. They do make a wider option but Ive only seen it in chrome.
However you might be in luck, as IIRC that's just vinyl with butyl or similar tape holding it on. I would contact a swimming pool vinyl liner company and see if they can cut you a strip you could then use to replace whats on there.
Heres a period correct Mustang option that might work. https://lmr.com/item/GE-N001RED/87-93-Mustang-GT-Red-Body-Molding-Stripe
Or you could try to contact one of the aftermarket auto body companies that make the 3m chrome trim and see if they have a red option. Just search "Auto body molding".