I was going to do all solids on Rhody trail (ok, I was going to use a variety of colors but the solids was the important design choice for me), ended up using prints for the colors. It would have been substantially the same look had I gone ahead and used all solids.. There is a crispness that I appreciate with all solids. Some people do the project with just one fabric for each color and it typically works just fine too.
I think in my desires to use up fabrics, I'm often using too many little bits/too many different fabrics and that maybe about 5 of each is all I need. Stash is not there yet though, still trying to use up 10" squares from swapping around Y2K.
That's the amazing thing, how we can all be working on the "same" project but some do it one size or another, or one set of fabrics or another. A lot of people don't do diagonal sets, and just something as simple as that can make a huge difference! Someone always comes up with something way different than the rest.