Can we let our helper wear uniform? Or only nanny wear uniform?

I have a friend from Thailand whose nanny wear uniform but they hire actual nanny like nurse who only take care of baby. No other house work. And I come across in some agency they have different types of staff; helper, nanny, butler, governess, etc. so just curious in Singapore are those normal helper wear uniform or is it the uniform staff. And also think they look neat and appropriate while taking care of baby.