UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(100, 200, 200, 40)];    UIColor *color = [UIColor redColor];

    textField.backgroundColor = [UIColor yellowColor];

    textField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"密码" attributes:@{NSForegroundColorAttributeName: color}];

    [self.view addSubview:textField];

  来自 http://code4app.com/snippets/one/UITextField设置placeholder颜色/537c765e933bf0a0468b525c#s0