The comedy-drama, from Gilmore Girls creator Amy Sherman-Palladino, follows a Las Vegas showgirl who takes on a role at her mother-in-law's dance school.
Addressing the show's official Twitter account, Grey's Anatomy creator Rhimes wrote: "Hey @abcfbunheads: really? You couldn't cast even ONE young dancer of colour so I could feel good about my kid watching this show? NOT ONE?"
When a fan argued that the show's dancing girls "were all different shapes & sizes", Rhimes replied: "I did love seeing girls of all shapes and sizes. That was great. Am a huge Gilmore Girls fan. Just pointing out one issue..."
HBO series Girls was also recently criticised for its lack of diversity, with producer Jenni Konner being forced to defend the show.
"I would also say that we're not trying to take on the world," said Konner. "We're trying to show a very specific group of people.
"But we are, I would say, regretful about sort of the lack of diversity in our show. And it's getting better. That's what I'll say. We're working hard on it."
Bunheads airs on Mondays at 9/8c on ABC Family.
Watch a promo for Bunheads below: