One of the managers at my work has decided to set up a 50g salt water tank in his office. He's a total newbie and I have been helping him. I asked him what type of fish he'd like and he said "colourful"

I'd like to make a fish list with him so he doesn't end up putting a fish in the tank that wouldn't be right in a 50g. He agreed that a list was a good idea. So I figured I'd ask for suggestions.
I was thinking wrasses (fairy and leopard) would be good, a dwarf angel and then I'm not sure so ideas please. I'm used to stocking very large or small tanks. A 50g seems tricky to me.