George, I don't think the cable jacket needs to be red. It just needs to be identified with the appropriate class (such as FPLR).
Your question was about jacketed cable, but when I buy 2-conductor "zip" cord FPLR cable, it's white. I don't see why it wouldn't be subject to the same color restrictions as jacketed cable, if there were any.
Also, I've seen jacketed 4-conductor UL-listed FPLR cable
offered in white, blue, green and yellow.