The singer, who is British, said she was made "ugly" for the Showtime series since Henry's fourth wife, Anne of Cleves, was not known as a particularly beautiful woman, People.com reported Friday.
"I enjoyed wearing the dresses," Stone said regarding filming her two-episode "Tudors" arc. "But the thing about Anne of Cleves is, she was not supposed to be attractive. Anne, let's be honest, was described as quite frumpy and ugly. But hey, I did it! I did my best! They had no problem making me ugly. Lots of makeup!"
The 22-year-old "You Had Me" singer did admit filming the final two episodes of the cable drama's third season in Ireland in 2008 had its ups and downs.
"It was cold, so in our off time we went to a lot of comedy clubs. The Irish are funny (expletive) -- they make me laugh," she told People.
2014: The Year in Music [PHOTOS]