Don't know, but I did find this book on quilt challenges
https://www.amazon.com/Quilt-Challen.../dp/1564779114
used copies are inexpensive, but read the reviews before you decide.
I'm guessing that you can use any challenge that specifies a block and just tell the members to use their school colors. The schoolhouse block might be a good one to pick:
http://www.quilterscache.com/S/SchoolhouseBlock.html