well in ba same rules applies to both cc and fc.
One of our FOs one morning was so scruffy (not shaved, hair in a mess, poor uniform standards) that captain and purser decided to offload him!!!
When u wear a uniform u have to wear it according to the standards, otherwise if that were true pilots could turn up for work in their pijamas!!!
BA has no problems with tattoos on the forearm but they will tell you to get all long sleeve shirts (which are quite nice and smart, I have to say!)
FBW