You could try Sewing with Nancy's "Versatile Ombre Quilting Part 1" which you can find at
http://video.wpt2.org/video/1530329782/. I think the second quilt on that show uses four ombre fabrics. She is pretty detailed in the video, but she also sells detailed printed information.
Similar to this is tube quilting or "Summer in the Park", which you can find at
http://www.youtube.com/watch?v=J5WgTyqB8Pc.
I did a small Summer in the Park and enjoyed it. I may also try one of Nancy's Ombre quilts.