I don't think it's going to. I'm fairly certain it shouldn't change if you made the field required by selecting it and choosing Object > Value > Type: User Entered - Required. Did you make it required in a different way? Like a script to verify if the field is filled prior to submitting/saving?
To change all fields at once, go in
File > Form Properties > Form Validation > Color Failed Fields and/or Color Mandatory Fields
uncheck the boxes