Yes. On Screen1 there is a property called Theme that allows you to select the theme for the app. This affects every screen in the application. Names with the
android: prefix reference the built-in names defined by Android. Names without the prefix reference names in the app package. The theme that is generated combines the AccentColor, PrimaryColor and PrimaryColorDark properties along with the Theme selection to yield the final look of the app.
Because the Theme property controls the look and feel of the whole app, we would need to change the property to be per-screen so that one screen could be transparent but not another, such as in your proposed splash screen example.