I think I know what to do!! It came to me while my husband and I were out planting our vegetables.
The main fabric--the same fabric as in the border--is a beautiful Autumn leaf pattern. I can just fussy cut some of those leaves and applique over the parts I'm not happy with--like falling leaves of Autumn. I think that will be really pretty. If I do it right, I might like it better that way. Time will tell. I still have three of the sun blocks to go, but I'll post pictures before summer is out, I'm sure. Stay tuned. And thank you all for your excellent suggestions.