The only deviations to the uniforms are really for us in First Aid (Grey polos with EMS and First Aid written on them), Security with their uniforms, Fire Department with dark navy or black Class B fire uniform shirts/pants. Maintenance with their jumpsuits or green work clothes. Safari in their beige outfits, and whatever the water show people wear (usually wetsuits and when not in that, usually a beige safari uniform) Flashpass in their fire-engine red shirts. Everyone else wears the neon-green polos with the exception of supervisors (They are issued a maroon colored "Leadership Team" polo, but can buy other colors) And some admin just wear a dress shirt and tie.
And then there is Loss Prevention which I will not discuss for obvious reasons.
Lifeguards and Water attendants wear swim suits with an identifying shirt. First Aid is the same as listed above. Security wears white polos and black/dark navy shorts or pants. Admin usually wear the Leadership Team polos, and everyone else again gets the neon-green polos.
If you want, I'll upload a pic of my First Aid uniform.
Long story short, if you don't know what department they are in, best bet is to look at the side of their ID card which is displayed. As you can see, mine that I posted above says "Safety." Others will say stuff such as "Ride-Ops" "Admissions" "Food Services" "Contracted" or sometimes even "Leasee"