I made a test square and it came out pretty small, about 4 in. by 4 in., and after I checked out some of the finished projects on Ravelry, I didn't like the look of an entire blanket of just those squares; they were way too busy. As I like the look of patchwork afghans, I decided to mix the "Peacock Feather Square" with a few different squares including "Double Crochet Granny Square" from Robyn Chachula's Crochet Stitches Visual Encyclopedia, Chris Simon's "Pavo Square" (I didn't notice for awhile, but apparently the square is named after a southern constellation called the Peacock), and "Openwork Square" and "Lacy Cross" from Jan Eaton's 200 Crochet Blocks.
Here is the pattern as originally planned, but I think I'm rotating the "Peacock" and "Double Crochet" squares so that the solid purple is parallel to the other solid colored squares.
If you can't read my writing, the bottom bit of the pattern lists 7 "Pavo" in green, 7 "Openwork" in blue, 7 "Cross" in gray, 42 "Double Crochet" in purple, and 42 "Peacock." I wanted a mix of open/lacy squares with more solid ones. The larger squares are about 8 in. by 8 in., to match the 4 in. by 4 in. of the "Peacock" and "Double Crochet" squares.
For the yarn, I went with Red Heart Super Saver, my go-to because it's easy to care for, has many shades, and is inexpensive. The green is Tea Leaf, the blue is Blue, the purple is Medium Purple, and the white is Soft White. The gray is Caron One Pound's Soft Grey Mix, because I couldn't find a Red Heart gray in stock that I liked.
As of today's date, I have all of the squares made and am about to start the seemingly, unending process of sewing them together with an invisible stitch.