"Celosia" (English) refers to the Celosia genus, the amaranths commonly known as cockscombs. (Wikipedia notes that the Greek root of the name means "burned;" I don't know if that's appropriate to add, but it is a clever reference to Team Flare.) "Cyane" possibly references Tillandsia cyanea, the pink quill. (It may also refer to the nymph of the same name.) "Calluna" (German) refers to the Calluna genus, or heather. "Cytisia" (Italian) refers to the Cytisus genus, or brooms. "Caléndula" (Spanish) refers to the Calendula genus, or marigolds.
Bonus: neither the Italian nor Spanish names refer to her signature color. However, both brooms and marigolds are nearly always yellow, purple's complementary color in painting. Arpha (talk) 20:34, 13 September 2013 (UTC)