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])

对于Swift 4.0, X-code 9.1版本或iOS 11，您可以使用以下语法来拥有不同的占位符颜色

textField.attributedPlaceholder = NSAttributedString(string: "Placeholder Text", attributes: [NSAttributedStringKey.foregroundColor : UIColor.white])

在我的例子中，我使用Swift 4

我为UITextField创建扩展

extension UITextField {
    func placeholderColor(color: UIColor) {
        let attributeString = [
            NSAttributedStringKey.foregroundColor: color.withAlphaComponent(0.6),
            NSAttributedStringKey.font: self.font!
            ] as [NSAttributedStringKey : Any]
        self.attributedPlaceholder = NSAttributedString(string: self.placeholder!, attributes: attributeString)
    }
}

yourField。placeholderColor(颜色:UIColor.white)

对于swift 4.2及以上版本，你可以这样做:

textField.attributedPlaceholder = NSAttributedString(string: "Placeholder Text", attributes: [NSAttributedString.Key.foregroundColor: UIColor.white])

我很惊讶这里有这么多糟糕的解决方案。

这里有一个永远有效的版本。

斯威夫特4.2

extension UITextField{
    @IBInspectable var placeholderColor: UIColor {
        get {
            return self.attributedPlaceholder?.attribute(.foregroundColor, at: 0, effectiveRange: nil) as? UIColor ?? .lightText
        }
        set {
            self.attributedPlaceholder = NSAttributedString(string: self.placeholder ?? "", attributes: [.foregroundColor: newValue])
        }
    }
}

提示:如果在设置颜色后更改占位符文本-颜色将重置。

对于目标C:

UIColor *color = [UIColor colorWithRed:0.44 green:0.44 blue:0.44 alpha:1.0];
 emailTextField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"Friend's Email" attributes:@{NSForegroundColorAttributeName: color}];

迅速:

emailTextField.attributedPlaceholder = NSAttributedString(string: "Friend's Email",
                             attributes: [NSAttributedString.Key.foregroundColor: UIColor.white])