Short natural colored hair, clean shaven, white collared button up shirts. Those are the staple uniform for males.

If you have the time and way of getting places, you could just do a walk through of MB and see how people look. You could also stop and speak with any of the workers there and just ask them about your concern.

Some info in this thread -

https://www.reddit.com/r/massachusetts/comments/x5uzk0/anyones_kiddo_gotten_a_job_at_market_basket_how/?utm_source=share&utm_medium=ios_app&utm_name=iossmf

Long hair is fine but has to be in ponytail if you work in a fresh department. Other than that, you have to shave everyday except for your mustache. You can have a porno mustache but no beard hair. You are required to wear a clean white dress shirt and tie.

My son has long hair and they wanted him to cut it. Ponytail wasn't acceptable to them.

I have seen guys at the one in Brockton with long hair. They looked pretty miserable with a hair net on. Not sure if the rules are uniform across all stores.

My experience as a customer for 30 years is that all of the employees are neat when it comes to hair, including facial hair. I've always assumed that it's a requirement there as it isn't the case at other grocery stores.

Nearly 20-30 kids I knew worked there throughout high school. If you’re a guy and go in with stubble or any kind of peach fuzz, they’re handing you a razor and sending you to the bathroom to shave it clean. This was only a few years ago. For girls there’s also rules but not sure on the specifics.