| | Re: What school/team colors are popular?
Blue and White is always popular. I'm from Alabama and it's Auburn - orange and blue (which is also Florida Gators but a little different shades) and Crimson and white for U of Alabama. Dallas Cowboys is always popular (lived there for 25 years) blue and silver.
You can do a web search for the big teams - maybe top 10 professional and college and get some ideas. Just include a description for "custom made for your school."
Also, you can go to the fabric stores like Hancock Fabrics and Joanns and look at the fabrics they have for schools. I am sure they have researched what is popular or they wouldn't be selling it.