Does the rainbow mochi taste like a rainbow? No. Is it still awesome mochi? YES! Froyo with rainbow mochi at Greenberry (not to be confused with Greenberry’s) in Rockville, MD.
Oh, temptation. The place is literally right across the street from where I live!
Daifuku mochi at Kotobuki in Washington, DC. There may be something more fun and tasty to eat than mochi, but I haven’t found it.