在Swift中这样使用，

 let placeHolderText = textField.placeholder ?? ""
 let str = NSAttributedString(string:placeHolderText!, attributes: [NSAttributedString.Key.foregroundColor :UIColor.lightGray])
 textField.attributedPlaceholder = str

在Objective C中

NSString *placeHolder = [textField.placeholder length]>0 ? textField.placeholder: @"";
NSAttributedString *str = [[NSAttributedString alloc] initWithString:placeHolder attributes:@{ NSForegroundColorAttributeName : [UIColor lightGrayColor] }];
textField.attributedPlaceholder = str;

添加带属性的占位符:

let attributes : [String : Any]  = [ NSForegroundColorAttributeName: UIColor.lightGray,
                                     NSFontAttributeName : UIFont(name: "Helvetica Neue Light Italic", size: 12.0)!
                                   ]
x_textfield.attributedPlaceholder = NSAttributedString(string: "Placeholder Text", attributes:attributes)

crubio对Swift 4的答案更新

选择UITextField并打开右边的标识检查器:

单击加号按钮并添加一个新的运行时属性:placeholderLabel。textColor(代替_placeholderLabel.textColor)

使用颜色作为类型并选择颜色。

如果您运行您的项目，您将看到这些更改。

为迅速

func setPlaceholderColor(textField: UITextField, placeholderText: String) {
    textField.attributedPlaceholder = NSAttributedString(string: placeholderText, attributes: [NSForegroundColorAttributeName: UIColor.pelorBlack])
}

你可以用这个;

self.setPlaceholderColor(textField: self.emailTextField, placeholderText: "E-Mail/Username")

在Swift 3.0中，使用

let color = UIColor.lightText
textField.attributedPlaceholder = NSAttributedString(string: textField.placeholder, attributes: [NSForegroundColorAttributeName : color])

在Siwft 5.0 +使用

let color = UIColor.lightText
let placeholder = textField.placeholder ?? "" //There should be a placeholder set in storyboard or elsewhere string or pass empty
textField.attributedPlaceholder = NSAttributedString(string: placeholder, attributes: [NSAttributedString.Key.foregroundColor : color])

yourTextfield.attributedPlaceholder = NSAttributedString(string: "your placeholder text",attributes: [NSForegroundColorAttributeName: UIColor.white])