Before you do anything, you might want to give Tony Garcia a call at Autobahn Interiors. He's a sharp guy and might be able to give you some ideas on what to do. In fact, if you take a look at his "gallery," you'll see some seats done in plaid (a different color combination than yours).
http://www.autobahninteriors.com/
My first reaction was that I didn't like the plaid, but it does sorta grow on you after awhile.