When entering or being at kindergartens, all teachers are required to wear the company t-shirts that we provide. In the case it is colder, we have some jackets, vest or t-shirts can go over your own long sleeve shirts.
Casual pants, khakis, comfortable sports pants or normal length shorts are all appropriate.
Wearing a suit or dress (unless it is a special event) would be too formal and not appropriate. On the opposite end wearing jeans, short shorts or pants with rips in them would be too casual or inappropriate as well. For women we would strongly advise against wearing a skirt or even dresses while teaching.