为什么CIFalseColor重新着色超过要求？

Question

在我的ViewController.viewWillAppear中：

super.viewWillAppear(animated)

var image = UIImage(named: "colorful")! 
let imageView = UIImageView(image: image)
imageView.frame.origin.x = 67.0
imageView.frame.origin.y = 324.0 - image.size.height - 20.0
view.addSubview(imageView)

var image2 = ImagePainter.paint(image: image, from: UIColor(red: 243.0/255.0, green: 209.0/255.0, blue: 0.0/255.0, alpha: 1.0), to: UIColor.blue)! 
let image2View = UIImageView(image: image2)
image2View.frame.origin.x = 67.0
image2View.frame.origin.y = 324.0
view.addSubview(image2View)

     

}

ImagePainter：

import UIKit
import CoreImage

class ImagePainter {

  static let context = CIContext()

  static func paint(image: UIImage?, from: UIColor, to: UIColor) -> UIImage? {
    guard let image = image,
      let inputImage = CIImage(image: image) else {
        return nil
    }
    let initFilter = CIFilter(name: "CIFalseColor")

    initFilter?.setValue(inputImage, forKey: "inputImage")
    initFilter?.setValue(CIColor(color: from), forKey: "inputColor1")
    initFilter?.setValue(CIColor(color: to), forKey: "inputColor0")

    guard let filter = initFilter,
      let filterOutput = filter.outputImage else {
        return nil
    }
    let cgimg = context.createCGImage(filterOutput, from: filterOutput.extent)

    let processed = UIImage(cgImage: cgimg!, scale: UIScreen.main.scale, orientation: .up);

    return processed
  }
}

CIFalseColor之前/之后：

此屏幕截图显示了原始图像（蓝色中的“来自”颜色）以及调用CIFalseColor的结果。没有任何色彩像我预期的那样。显然我做错了什么，但是呢？