I do remember those. I had just started quilting and the first ones to show up were all very color-wheel orientated. I loved the look of that - and I tend to gravitate toward those types of quilts.
Here's a picture of how one quilter put together the squares:
http://3.bp.blogspot.com/_6jvqpaoQet...lt+-+Heidi.jpg
Great lesson in value placement.
This site has a lot of links related to Millenium quilts:
http://www.quiltville.com/y2kquilt.htm