AngularJS set form to initial state - angularjs

Question

I have a form which once submitted, I want to clear all fields and set to it initial state.
I use $scope.form.setPristine(); but field labels keep red color.
How can I avoid this?
EDIT:
Here i post the code. All works fine except by such issue.
Html:
<form name="change_password" novalidate>
<md-input-container style="margin:0;width:200px" flex>
<label>Enter your current password</label>
<input name="password" type="password" ng-model="password" ng-minlength="7" required>
<div ng-messages="change_password.password.$error" ng-if="change_password.password.$dirty" role="alert">
<div class="error_form" ng-message="required">Enter your current password.</div>
<div class="error_form" ng-message="minlength">Password must be at least 7 characters long.</div>
</div>
</md-input-container>
<md-input-container style="margin:0;width:200px" flex>
<label>New Password</label>
<input name="new_password" type="password" ng-model="new_password" ng-minlength="7" required>
<div ng-messages="change_password.new_password.$error" ng-if="change_password.new_password.$dirty" role="alert">
<div class="error_form" ng-message="required">Enter your new password.</div>
<div class="error_form" ng-message="minlength">New password must be at least 7 characters long.</div>
</div>
</md-input-container>
<md-input-container style="margin:0;width:200px" flex>
<label>Confirm new password</label>
<input name="re_new_password" type="password" ng-model="re_new_password" ng-minlength="7" required>
<div ng-messages="change_password.re_new_password.$error" ng-if="change_password.re_new_password.$dirty" role="alert">
<div class="error_form" ng-message="required">Confirm your new password.</div>
<div class="error_form" ng-message="minlength">New password must be at least 7 characters long.</div>
</div>
</md-input-container>
<button class="button" style="width:200px" ng-if="!saving" ng-click="save_password()" ng-disabled="is_uploading || change_password.$invalid || new_password!=re_new_password">Save new password</button>
<div ng-if="saving" layout="row" layout-align="center center">
<md-progress-circular md-mode="indeterminate" size="22"></md-progress-circular>
</div>
</form>
Ctrl:
userService.save_password($scope.password, $scope.new_password).then( function(response) {
$scope.$apply( function() {
if ( response.result ) {
$scope.password = '';
$scope.new_password = '';
$scope.re_new_password = '';
console.info($scope.change_password);
$scope.change_password.$setPristine();
}
showMessage(response);
$scope.saving = false;
})
})

Answer 1

You misunderstand
setPristine();
It only clears classes on your form, nothing else. Variables are still set. You need to do it like below:
$scope.emptyModel = {};
$scope.reset = function() {
$scope.yourFormModel = angular.copy($scope.emptyModel);
$scope.user_form.$setPristine();
$scope.user_form.$setUntouched();
}

Answer 2

Reset with $setPristine and $setUntouched (for your fiddle):
$scope.user_form.$setPristine();
$scope.user_form.$setUntouched();