Attempting to use "§" accompanied with any compatible characters for formatting codes for names in realms causes the realm name to default to the preivous name and remain near unchangeable depending on what version you use, but the behavior is still the same:

Name attempted
"§k| §r §l §5 The End Realm §r §k|"

Defaults to
"EnderSteve04's Realm"

Additional Behaviors
Name remains unchangeable to any other name under most circumstances, and refuses to change to any realm name with formatting codes in it, this results in the specified realm being unable to have its name changed. Note that imported worlds onto the realm with formatting codes (§) do not change the realm's name.