There are variations on dango flavorings. Sometimes matcha (powdered green tea) is added, and in the norther island of Hokkaido, potato flour is used instead of rice flour. Sometimes they are coated or filled with red bean paste.
I've never attempted to make them myself, but I found this recipe online and it looks easy enough! For those who wish to buy prepared dango but don't have access to a Japanese grocery, Mitsuwa's online store offers dango covered with sesame seed paste.
Related: DIY Mochi Ice Cream Balls
(Image: Kathryn Hill)