On CQ4Newbies, there are two color study round robins going on, neither of which I joined, but I have been doing my own by myself. I'm told that's called a "nesting robin". The first one to begin is for green, and I worked on a block for Carole in AZ (January post "Seein' green") after doing my own, which the last picture in this post. The second one that has not quite begun yet is for the color purple.
While I was searching my stash for purple fabric, I decided to pull all the fancy blues and yellows I had at the same time. By fancy, I mean silks, satins, brocades, velvets, etc. My green block is all fancies, so I've chosen the same for the other colors so far....one exception being the patch in the center of the yellow block, which is a cotton print. I've pictured it here at the point where it is simply pinned. All the fabrics are in place, and I will now hand baste it with a contrasting thread and baste all around the outer edge. If I was to decide at this point that I didn't like one or more of the patches, I could easily replace any of them; a distinct advantage over the "sew and flip" method of piecing.
Here's the all blue block. If I had used all the blues I have, I could have made it twice as big without repeating fabrics, but some of the blues I have are a little too aqua-ish to look good with the true blues. Just my opinion, of course.
And the all purple block. Oddly enough (having omitted the greenish blues from the blue block), it didn't bother me to use the reddish purples with the blueish ones.
The all green block in its finished state. Click on the pic for a larger version to see details. Check out that frog trio in the lower right corner.....