title: NSWindow color not changing if I am using it as NSSheet. How resolve this issue?
body: <p>I know it seems to be a trivial question however I am facing hard time to find a solution.</p>
  
  <p>Please let me explain what I am doing.</p>
  
  <p><strong>How I am changing NSWindow background Color</strong></p>
  
  <p><a href="https://i.stack.imgur.com/K11CN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/K11CN.png" alt="enter image description here"></a></p>
  
  <p>I have generated a <em>User defined runtime attributes</em> Key <strong>backgroundColor</strong> of type Color for the NSWindow</p>
  
  <p><strong>Issue</strong></p>
  
  <p>The above way is working fine however when I am calling the NSWindow as NSSheet then the color of window is not changing.</p>
  
  <p>Please suggest some solution for the issue. Many thanks.</p>