Transparent Header in NavigationExperimental

it's been a while since i am trying to make the header bar transparent in react-native with NavigationExperimental but no luck, can any one tell me how to do it ?

here's my code

return (<NavHeader
      {...props}
      style={styles.headerStyle}
      renderTitleComponent={this.renderTitleComponent}
      renderLeftComponent={this.renderLeftComponent}
    />);

and the headerStyle

 headerStyle: {
    backgroundColor: colors.appBarBackgroundColor,
    borderBottomWidth: Platform.OS === 'ios' ? StyleSheet.hairlineWidth : 0,
  },

Edited: Here's the color used in the project

errorColor: '#d31100',
primaryColor: '#292929',
secondaryColor: '#929292',
controlColor: '#212121',
secondaryControlColor: '#ffb300',
appBarBackgroundColor: 'transparent',

Thanks