I think that would be darling if you used some fabric for the circles and made it a raw edge applique. Sometimes I have tiny scraps of favorite fabrics and this would be a fun way to use them! Just fuse them on and do the cute topstitching over them.
I thought of that while it was stitching, how cute it would be with fabric......then one could just stitch the outlines and not the fill.......
Reminds me of how my trees all burst out into color this time of year. Even my Ginkgo Biloba is surviving the drought. Well done!