bigfootlarry, I checked the trim code for all three model years and they all say Medium Blue. When you ordered the carpet from Ford the letter B was used and all the listing indicated was blue. Auto Custom Carpet (ACC) manufactures the majority of carpet for the aftermarket. They will let you request up to five carpet samples so you can compare it to non faded section of your carpet.(800-352-8216) I had to do the same on my 85 GT's red carpet. Ford only listed one color, everyone else listed several. They send the samples and I was able to compare and order the right color. SMS also will let you order interior samples as I have used them for seat and carpet material for my 71.
http://www.smsautofabrics.com/request-samples.php