title: How to apply filters/color on selected image area in iOS SDK
body: <p>I have an image of a my face and I just want to apply some filter or color on lips/eyes etc. I have detected the areas but my issue is how to add color there so that is looks natural and mix with existing image.</p>
  
  <p>Please see the image below to have better idea what I need. See color applied on lips which is pretty much natural,</p>
  
  <p><img src="https://i.stack.imgur.com/RVhCh.png" alt="enter image description here"></p>