Do I Need Permission From My Boss To Color my Hair? Leo and Rebecca Hash Tag Topic

Leo and Rebecca Hast Tag Topic - #canicolormyhair
Guys, been working at my new job for about 2 months and the other day I told a co-worker I was gonna change the color of my hair. She said 'You Better Ask The Boss Before You Do That". I laughed and she didn't. She said she was being serious and that was that. WOW...has anybody even heard of something so stupid. Is that even legal?