Backspace character ⌫ is blue

My iOS app has a custom keyboard. I recently changed the backspace key glyph from ⬅️ to ⌫. The character is blue. All keys on the keyboard are created by the same code, and no other character does this. I looked around on the web, found several complaints about blue backgrounds for things like backspace and shift keys, but nothing about the character itself being blue. The character does not appear blue when I paste it into text. Does anyone have a clue?