无法更改翻转的UIImage图像的tintColor Swift 2 iOS

import UIKit
import CoreImage

func tintImage(image: UIImage, color: UIColor) -> UIImage? {
    guard let ciImage = CIImage(image: image) else {
        return nil
    }
    
    let filter = CIFilter(name: "CIMultiplyCompositing")!
    filter.setValue(ciImage, forKey: kCIInputImageKey)
    
    let ciColor = CIColor(color: color)
    let colorFilter = CIFilter(name: "CIConstantColorGenerator")!
    colorFilter.setValue(ciColor, forKey: kCIInputColorKey)
    
    let colorImage = colorFilter.outputImage!
    filter.setValue(colorImage, forKey: kCIInputBackgroundImageKey)
    
    guard let outputImage = filter.outputImage else {
        return nil
    }
    
    let context = CIContext(options: nil)
    guard let cgImage = context.createCGImage(outputImage, from: outputImage.extent) else {
        return nil
    }
    
    return UIImage(cgImage: cgImage)
}

// 使用示例
let originalImage = UIImage(named: "originalImage")
let tintedColor = UIColor.red
let tintedImage = tintImage(image: originalImage, color: tintedColor)