How to call react-native-firebase notification.android.setLights method

I cannot get the LED indicator to work with the setLights method provided by react-native-firebase. I'm not sure whether this is a bug or I am not passing the parameters in correctly.

I am calling the method like so:

const channelID = 'test-channel';
const channel = new firebase.notifications.Android.Channel(
    channelID,
    'Test Channel',
    firebase.notifications.Android.Importance.Max,
)
.setDescription('Test notification channel');

firebase.notifications().android.createChannel(channel);

const notification = new firebase.notifications.Notification()
    .setTitle('test title')
    .setBody('test body')
    .setSound('default');

notification
    .android.setChannelId(channelID)
    .android.setSmallIcon('icon')
    .android.setLights(0xffffffff, 500, 500);

firebase.notifications().displayNotification(notification);

I am unsure what format the first number should be in. My understanding is that it is converted to Android's ARGB format, so I assumed it should be a hex number but that may be incorrect.