Upon closer inspection, I realized that she used ordinary crayons to color the quilt, and then hand sewed the outline with black thread. She also used buttons to give some dimension to the center and two of the inner rows.
Carol (aka MamaCJT) used a free mandala design that she downloaded from Eye Pop Art. Look down the left column for the “Free Coloring Pages“. It’s a 5-page PDF file.
On one of her other blog posts she provides a tutorial on how to color on fabric with crayons, entitled The Crayon Method.
What a delightful project. I am truly inspired to do this! Thanks, Carol!