title: How can I change a label background color in a WPF form, by clicking a button in a WinForms form?
body: <p>In my program I have two windows opened at the same time, one is a WPF form and the other one is a WinForms form.</p>
  
  <p>I need to change a label background color that's on a WPF form, by clicking a button that's placed on the WinForms form.</p>
  
  <p>How can I do it?</p>