title: How to get RGB values of a pixel in JavaFX
body: <p>I am getting started with JavaFX and basically what I am trying to implement is a Color Picker.
  At first, I thought of having a rectangle with a LinearGradient that goes through all primary/secondary colors.</p>
  
  <p>Looks like what I want, but the problem is that I can not get the RGB values at a given coordinate(x,y) in this Node.
  I know you can do it through the fill property of any Shape IF it is a Color.</p>
  
  <p>But Is there anyway to get the RGB values of anything inside a LinearGradient/Paint ?</p>