The blue highlighting that each form field displays in Adobe Acrobat/Reader is a setting of the application, not of the document.
You can switch it off by going to Edit - Prefs. - Forms, and tick off "Show
border hover color for fields".
Since it is a feature of Acrobat/Reader to show/highlight the fields, when you send your PDF to other users the fields would still be highlighted unless they also had turned off the setting.