#.stevenp
sand silo
olive cobalt
https://stripe.com/docs/stripe-apps/reference/app-manifest this is what's documented there and as long as the icon is at that path and has the right size it should work.
What are you seeing exactly? Is there any error in the console or equivalent?
I think that icon only works when the App is installed/discoverable and no when you're previewing the app itself but I don't know much more about this @echo summit unfortunately.
I'd recommend contacting our support team directly to follow up: https://support.stripe.com/contact