The rainbow starter bundle above will get you well on your way to having a great selection of fabrics for your Magical Unicorn quilt.
Depending on your specific color choices, you may need to add to this selection. You will also need to add larger cuts of some colors due to size and background needs. Alison has add-on options with the bundle and you can also visit the yardage section in her online shop for the white base/background fabric.
I want to add that I’ve been sewing with Alison’s fabric on two of the Bullseye quilts and it is a joy to work with. It will be a constant in my stash from now on. Happy stitching!