My mother hates the way I dress...?

It's getting ridiculous. I'm twenty years old for christ sakes! Whenever I go over to her house or we go somewhere she's got something so say or a little comment to make. I have dreads, tattoos, stretched ears, piercings etc. and pretty much wear whatever I feel like. I understand I'm not necessarily every mothers dream for their 'little girl' but I'm a grown woman and it's becoming intolerable lol. She will even discuss it over family events like birthdays and things. She was born and raised in Africa and has ideas about how women 'should' look. How do I let her know enough is enough, as it always ends in arguments...