Ion Tabs properties - how to use?

Ionic Framework
1

This is my code:

<ion-tabs>

  <ion-tab-bar slot="bottom">
    <ion-tab-button tab="tab1" ripple-color="success" color-selected="success">
      <ion-icon name="information-circle-outline"></ion-icon>
      <ion-label>info</ion-label>
    </ion-tab-button>

    <ion-tab-button tab="tab2">
      <ion-icon name="paper"></ion-icon>
      <ion-label>guidelines</ion-label>
    </ion-tab-button>

    <ion-tab-button tab="tab3">
      <ion-icon name="checkbox-outline"></ion-icon>
      <ion-label>checklists</ion-label>
    </ion-tab-button>
  </ion-tab-bar>

</ion-tabs>

Icon changes work, but the color change attempts on Tab 1 do nothing.

What am I doing wrong? Looks so simple in the docs!