title: Interface Builder background color => clear color?
body: <p>I've setup some background colors for my Labels in order to position them. Now that they are well in place, I would like to reset their background color to none, or clearColor.</p>
  
  <p>But I don't find any way to achieve this in IB, I don't find any "no color" color...</p>
  
  <p>Is there any way to do this without re-coding color at runtime?</p>