JSFiddle - React, Tailwind, and code Playground

HTML

<div class="ui-dialog-footer ui-widget-content ng-tns-c1-1">
  <!---->
  <button pbutton="" type="button" class="ng-tns-c1-1 ui-button ui-widget ui-state-default ui-corner-all ui-button-text-icon-left"><span class="ui-button-icon-left ui-clickable fa fa-fw fa-check"></span><span class="ui-button-text ui-clickable">Yes</span></button>
  <!---->
  <button pbutton="" type="button" class="ng-tns-c1-1 ui-button ui-widget ui-state-default ui-corner-all ui-button-text-icon-left"><span class="ui-button-icon-left ui-clickable fa fa-fw fa-close"></span><span class="ui-button-text ui-clickable">No</span></button>
</div>

CSS

.ui-dialog-footer .ui-button {
      background: green;
    }
    
    .ui-dialog-footer .ui-button + .ui-button {
      background: red;
    }