User blog comment:Jo SHININGSTAR/Go! Princess Precure OP/@comment-25034020-20150211092542/@comment-25034020-20150213044234

Cure Scarlet was even introduced herself as "Princess of crimson fire, Cure Scarlet" so she is most likely based of fire. The merchandise with the purple Princess perfume sticky notes I think is fake. I think it's just used because they can't think of another colour for the merchandise.