It's not quite the same, but I worked at a whole foods that had issues with hair too. The boss actually said that when he was given the store, he could run it like it was his own business. He then proceeded to do so. A few girls with dyed hair were told to either dye it back to normal/ cover it up/ or find another job. I was told that if my hair got too long to fit under a hair net, I'd have to choose between my hair and my job. Long story short, I didn't let him stop me. I made a stink about it to corporate, and all of a sudden he started letting us wear a few different types of hats. One was a tam.
There are some times that you really can fight the system and they can't do anything to you. Don't give in. They can't suspend you for having locks. They can look down on you, but who cares what they think?
Moral of the story: don't work for whole foods. lol.