>>7217621Her dress color has never been consistent in marketing or merchandise. as
>>7217630 said one of the reasons why it's been promoted as blue is due to the coloring during some of the ballroom scene.
Her dress "solidified" as blue when Disney decided to go full-throttle with the Disney Princess line, and so the two blonde princesses at the time became "pink" Aurora and "blue" Cinderella. Though, she was definitely marketed in a blue dress way before Disney ever created the Disney Princess line.