I set the uniforms (Maxis outfits) for some employees at my restaurant, only one waitress changed into her outfit. I did save them as business outfits for anyone else hired to wear. The host, cook and another waiter will not change into their outfits, while I'm there as owner, or if I visit the diner as a customer.
Comments
Unlike in the future games, you'll have to change employees' uniforms one employee at the time. Saving uniforms are only there for you to save time (and to have them have a different haircolor at work). Do remember that uniforms for employees and the business owner may change their facial feature, change their eye colors to brown and remove their glasses, eyebrows, make-up, jewellery and facial hair by some unfixed bug.
I did change them one at a time, none bothered changing except one of them as I said.
Hmm...
Try asking those who don't wear it to wear it. Or design a new uniform for them (can be same). See if those work.