;'> parent black opacity 0.2 and child blue </div>
</div>

<div style="background-color:rgba(0,0,0, 0.2); margin-top:50px;">
  <div style='color:red;'> parent black alpha 0.2 and child blue </div>
</div>

<div style="background-color:black; opacity: 0.2; margin-top:50px;">
  <div style="background-color:black;">
      <div style='color:red;'> parent black opacity 0.2 and child blue </div>
</div>
</div>

<div style="background-color:rgba(0,0,0, 0.2); margin-top:50px;">
    <div style='color:red;'> parent bla