title: how can I change the color of Toast depends on message type in Angular material $mdToast?
body: <p>While using <code>$mdToast.simple().content("some test")</code> it is showing the toast with black color. how can I change that color to red, yellow and so, depends on the type of the error messages like error, warning and success.</p>
  
  <p>Similar question as <a href="https://stackoverflow.com/questions/34614767/how-to-show-md-toast-with-background-color">this</a>.</p>