Is there a way to have different images for favicon and app icon?

Hey all,

Love Generate Press. Is it possible to use separate images for the favicon and the App icon?

The Customizer only allows you to upload a single 'Site Icon' which it uses for both, but unfortunately this doesn't work for me as I want a favicon with a transparent background and an app icon with a white background. But when I upload a .png or .ico the favicon looks great but the app icon is all black (transparent background seems to default to black and my letters are black).

Suggestions?

Thanks,
Adam