It's so exclusive to the US that I didn't even understand what OP was saying before reading the comment section for clues.
Blue bubbles, green bubbles? Wtf is that and how is it related to Android/iOS.
For reference, I live in South East Asia and use Android, but I have never heard my friends using iOS complain about some kinda bubble colour.
If your name consists of non-ASCII characters, like Thai words or Arabic or Chinese, it's pretty easy to rack up >15 bytes in your username alone.