Hello,

Thank you for the question regarding Crosslight.

Basically, Crosslight has yet to provide cross platform styling feature.

However, you could customize your component style on each view level.
In iOS platform, it could be done in ViewController level; in Android platform, in Activity or Fragment level; in Windows Phone 8 and Windows 8, in Page level.

Yes, you also can customize your component style programmatically.
Crosslight developer team has provided the sample regarding this scenario.
You could check out the sample from this link below:
http://git.intersoftpt.com/projects/CROS/repos/samples/browse/DrawerSamples

This snippet example code below is how to re-styling in ViewController in iOS platform.
(http://git.intersoftpt.com/projects/CROS/repos/samples/browse/DrawerSamples/FacebookStyle/DrawerSamples.Facebook.iOS/ViewControllers/MainDrawerViewController.cs)

You could customize your own style in InitializeView() event.

protected override void InitializeView(){
base.InitializeView();

            var searchButton = new UIBarButtonItem(UIBarButtonSystemItem.Search);
            // handle searchButton's Clicked event, or assign a command to be called in ViewModel.

            // add a custom left button item to our view
            this.LeftButtonItem = searchButton;

            // customize the right button item which automatically open/close the drawer
            this.RightButtonItem = new UIBarButtonItem();
            this.RightButtonItem.Image = UIImage.FromBundle("UserList.png");
}

Hope this helps.

Regards,
Hans K.