The nursery is painted a lime green color with this Geo Girl bedding from Target, so I wanted to use crepe paper colors that coordinated with the bedding: light pink, dark pink, blue, purple and white. I couldn't find any purple crepe paper at Wal-Mart, so I just got purple tissue paper and used that instead. The end result is similar, but it is certainly more slippery to work with. I just lined the tissue paper up on my cutting board, cut the width into 1 1/4 inch strips, and started rolling and gluing.
Also these rosette balls are available in my etsy shop here, with the colors customized to your preferences.