In the home where my grandmother lived the cleaning crew all wore a certain colors scrubs.

At the one my mother hung out it, they wore very boring pants and tops, nothing regulated or regimented. Rubber gloves though, were part of the outfits.

Scrubs at all local nursing homes in my area. Usually the cheapest variety provided.

khakis and scrub shirt or blue polo with name of facility

It varies from place to place, but the private ones will be more varied and lenient regarding what janitorial staff wear. In the private one I worked, they wanted staff, visitors, and especially residents to be able to tell if someone was an employee just by what they wore. So maintenance and janitorial men wore ball caps (indoors and out) and the women wore scrub tops and any sort of pants that were not blue jeans.