Styling segment on ios ionic/react

Ionic Framework
1

Styling background color of segment button is not working on ios style. Styling on ios is not working

<IonSegment className="segment-btn" color="dark" onIonChange={e => console.log('Segment selected', e.detail.value)} value="chapter">
          <IonSegmentButton value="term">
            <IonLabel>Term</IonLabel>
          </IonSegmentButton>
          <IonSegmentButton value="chapter">
            <IonLabel>Chapter</IonLabel>
          </IonSegmentButton>
        </IonSegment>

And the css

.segment-btn{
  --background: #FCB589;
}
2

It works if you remove color="dark".