Ionic 2 Tab color change with events

How can I change the tab color using an event? For example I am adding a product to cart. Raise the number of cart while doing so. But instead of this, I added the cart product and I want to change the color of the cart tab option. How can I do it ?

<ion-tabs no-border>
  <ion-tab [root]="tab1Root" tabTitle="Giriş" tabIcon="ios-home"></ion-tab>
  <ion-tab [root]="tab2Root" tabTitle="Ürünler" tabIcon="ios-pizza"></ion-tab>
  <ion-tab [root]="tab3Root" (ionSelect)="barkodTara()" tabTitle="Barkod" tabIcon="ios-barcode"></ion-tab>
  <ion-tab [root]="tab4Root" tabTitle="Hesabım" tabIcon="ios-contacts"></ion-tab>
  <ion-tab [root]="tab5Root" tabTitle="Sepet" tabBadge="{{ SEPETSAYISI }}" tabBadgeStyle="danger" tabIcon="ios-cart"></ion-tab>

for example, can I do this with the help of a class?