They spell it “JetBlue” when typing it (check the official JetBlue website) and “jetBlue” on their planes (check Google images for example). I don’t see anything wrong.
Yeah it does get confusing. Their logo is “jetBlue” ; however, when they are typing it in text format they put it as
“JetBlue” most of the time. I understand where your coming from though. I had to do research before replying.