await CrossShare.Current.OpenBrowser("https://auth.xamarin.com/account/register",
    new BrowserOptions
    {
        ChromeShowTitle = true,
        ChromeToolbarColor = new ShareColor
            {
                A=255,
                R=118,
                G=53,
                B=235
            },
        UseSafariReaderMode = false,
        UseSafariWebViewController = true
});