How to use the react-native-ui-lib.Colors.rgba function in react-native-ui-lib

style={{
          position: 'absolute',
          alignSelf: 'flex-start',
          padding: 20,
          opacity: animationValue2,
          transform: [
            {scale: animationValue2}
          ]
        }}
      >

fontFamily: Constants.isAndroid ? 'sans-serif-bold' : '.SFUIText-Heavy',
        alignment: 'center',
      },
      subtitle: {
        color: Colors.white,
        fontSize: Typography.text80.fontSize,
        fontFamily: Constants.isAndroid ? Typography.text80.fontFamily : '.SFUIText-Medium',
      },
      backButton: {
        // visible: true,
        color: Colors.white,
        showTitle: Constants.isIOS ? false : undefined,
        testID: 'pop',
      },
      leftButtonColor: Colors.white, 
      leftButtonDisabledColor: Colors.rgba(Colors.white, 0.6),
      rightButtonColor: Colors.white, 
      rightButtonDisabledColor: Colors.rgba(Colors.white, 0.6),
    },
  };
}

},
      subtitle: {
        color: Colors.white,
        fontSize: Typography.text80.fontSize,
        fontFamily: Constants.isAndroid ? Typography.text80.fontFamily : '.SFUIText-Medium',
      },
      backButton: {
        // visible: true,
        color: Colors.white,
        showTitle: Constants.isIOS ? false : undefined,
        testID: 'pop',
      },
      leftButtonColor: Colors.white, 
      leftButtonDisabledColor: Colors.rgba(Colors.white, 0.6),
      rightButtonColor: Colors.white, 
      rightButtonDisabledColor: Colors.rgba(Colors.white, 0.6),
    },
  };
}

},
    trackDisabled: {
      backgroundColor: INACTIVE_COLOR
    },
    minimumTrack: {
      position: 'absolute',
      backgroundColor: minimumTrackTintColor
    },
    thumb: {
      position: 'absolute',
      width: THUMB_SIZE,
      height: THUMB_SIZE,
      borderRadius: THUMB_SIZE / 2,
      borderWidth: BORDER_WIDTH,
      borderColor: Colors.white,
      shadowColor: Colors.rgba(Colors.black, 0.3),
      shadowOffset: {width: 0, height: 0},
      shadowOpacity: 0.9,
      shadowRadius: SHADOW_RADIUS,
      elevation: 2
    },
    activeThumb: {
      width: THUMB_SIZE + 16,
      height: THUMB_SIZE + 16,
      borderRadius: (THUMB_SIZE + 16) / 2,
      borderWidth: BORDER_WIDTH + 6
    },
    touchArea: {
      ...StyleSheet.absoluteFillObject,
      backgroundColor: 'transparent'
    }
  });