message: change right panel/event tile hover bg color
diff: $bg-color: #15191E;
  $base-color: $bg-color;
  $base-text-color: #ffffff;
  -$header-panel-bg-color: #22262e;
  +$header-panel-bg-color: #20252B;
  $header-panel-border-color: #000000;
  $header-panel-text-primary-color: #B9BEC6;
  $header-panel-text-secondary-color: #c8c8cd;
  