Defina a cor do White Place em Swift
placeholderLabel.textColor (Swift 4)
_placeholderLabel.textColor (Swift 3 or less)
Frail Flamingo
placeholderLabel.textColor (Swift 4)
_placeholderLabel.textColor (Swift 3 or less)
myTextField.attributedPlaceholder = NSAttributedString(string: "placeholder text",
attributes: [NSAttributedString.Key.foregroundColor: UIColor.white])