When I worked in fast food in 2018, we weren't allowed to have any flashy makeup or weird hair. Everything had to be neat in your appearance. I can tell you that all the girls who worked for us looked the same, like a gray mass with dull haircuts.
If your workplace has strict rules about hair, but you still want to look cool, you can use these many medium length haircuts ideas on glaminati.com/medium-length-hairstyles-long-thick-hair/. These hairstyle posts are updated very often with new trends, so you're sure to find something trendy here :)