This demo/module shows you how to create a color picker using JavaScript and Gestures.
Any image can be used and it's pixel color data obtained by tapping or dragging around the image.
or for the most updated version: View on GitHub
Note that this demo will not run in debugger due to requiring localhost JavaScript HTTP requests to serve the image data from cache.
There is also a specific module available for the Quasar RBG Controller. For more information see this page.