While at Disney for 4 days wearing my brown Sprints, I saw approximately 20-25 people with them each day. I did see nearly 40 people with VFF at Epcot the day I was at the park. It was pretty enlightening to see a WHOLE family of 5 with VFF at Epcot.
Do you have a picture of your brown sprints that you can post on the forums? I have never seen that color, unless you mean the taupe which is lighter, almost tan. I have Brown/Brown KSOs and Walnut/Brown Classics. Don't ever recall seeing a brown offering in the Sprints.