Definir alteração de cor do ícone metroal

class Utilitybar extends React.Component {
  constructor(props) {
    super(props)
    this.onButtonClicked = this.onButtonClicked.bind(this)
    this.state = { currentButton: null }
  }

  onButtonClicked (id) {
    this.setState({ currentButton: this.state.currentButton === id ? null : id })
  }

  render(){
    return (
      <div>
        <IconButton
          color={this.state.currentButton === 0 ? "primary" : "default" }
          onClick={() => this.onButtonClicked(0)}>
          <FaPlayCircle/>
        </IconButton>
        <IconButton
          color={this.state.currentButton === 1 ? "primary" : "default" }
          onClick={() => this.onButtonClicked(1)}>
          <FaRegFileAlt/>
        </IconButton>
      </div>
    );
  }
}
Mystic Dev