title: How to display a color selector when clicking a button?
body: <p>I'm making a program that draws some shapes and fills them with color. I need to change the 'line' color, and want the user to be able to select the color.</p>
  
  <p>How can I, when clicking a button "Choose Color", have a set
  of colours appear below the button? Is it possible for the selector to be embedded in the UI below the button (and not pop up in a window)?</p>
  
  <p>I want to display a color selector like in Paint.</p>