Calling those working as Vets and Vet Techs

How strict is your job on visible piercings, tattoos or unnatural hair color? 
I am probably going to college in the fall to be a vet tech but I do want a few facial piercings (nose mainly) 
I do want to know how strict they are with those kinds of things, as I've seen some local vets and their assistants with visible tattoos and piercings.