White Label for Google, Facebook and Twitter Sign-in Page for Agency

As an agency account owner, I would like to make the Google, Facebook and Twitter signin page, after clients clicking on signin using Google, Facebook or Twitter, to be whitelabeled. Or, if it is not possible, I would like to have the option of turn off or on Google, Facebook or Twitter signin options on the login page under my domain. As of now, after clicking the signin tab for Google, Facebook and Twitter, all clients would see Followr brand or Followr domain. Please support this if you are an agency account holder by up vote this. Please give me some feedbacks. Thank you.