Perhaps Oda was just telling us that he is not blue. Since names do not need to exist in order to be used, or be some sort of verb-related word, I suppose he could choose whatever method he wants.
[One Piece Future-Character-Naming Convention]
Oda: Hmm. We need a name for this guy with horn-like hair.
Asst #1: Bull-sama!
Asst #2: Blue! He looks depressing.
Oda: Blue? No.
Asst #2: Eh?? Baloonoe?
Oda: Eh!? Blue…no?
Asst #2: Blueno!
Oda: …........
Sanji: You shitty bastards!!wow. I am…
That just made my day…