I've been working on the piece that uses two colors. Its reversible and has a rib-type pattern. I had to start over several times and finally determined that there was a discovered a mistake in the pattern after about 5 attempts but I'm having fun with it now that I've figured it out. The number of stitches you cast on need to be in multiples of 3 and you'll need to use circular or double pointed needles if you use 2-colors. On one side you'll have one color on the top of the rib and on the other side the second color will be hightlighted.
The basic pattern is:
Row 1: With color A yo, sl1 [k2tog, yo, sl1] repeat. Slide all stitches to other end of needle.
Row 2: With color B p2tog [yo, sl1, p2tog] repeat.
Row 3: With A, yo, sl1 (p2tog, yo, sl1] repeat. Slide all stitches to other end of needle.
Row 4: With B, k2tog, [yo, sl1, k2tog] repeat.
When I showed a picture of this to my very-smart niece, she said, oh, like a broiche pattern. And that's exactly what this is! Sorry I can't display a picture of my product - its a gift for someone who might read this posting.
And for you visual learners, here's a couple videos from youtube show 1-color brioche and 2-color brioche