title: UIImageView tintColor wrong on device
body: <p>I have a UIImage and a UILabel next to one another, and set the label textColor and the imageView tintColor UIColor.purple.
  However, on the device, the purple on the image is darker, it looks fine in the simulator though. I checked in the view hierarchy debug, and indeed the label has 0.5, 0, 0.5 as textColor, but the imageView has 0.4, 0, 0.4 as tintColor for some reason.</p>
  <p>I tried setting 0.6, 0, 0.6 on the imageView, and it resulted in the tintColor being 0.48, 0, 0.48.</p>
  <p>Any idea why that is ? I don't want the SDK to adjust my colour in any way, I just need the tintColor to be what I set it to be.</p>
  <p>The code is quite simple here:</p>
  <pre><code>    titleLabel.textColor = .purple
      imageView.tintColor = .purple
  </code></pre>
  <p>I also noticed that setting the tintColor to .purple on the UILabel also results in it having 0.4, 0, 0.4 as tintColor rather than 0.5, 0, 0.5 as with textColor. For some reason the tintColor property edits the color it's given.</p>