Explanation
A theme is a collection of templates and stylesheets that define the layout and appearance of an application.
You can create a custom theme for an application by using the Create Theme Wizard or by copying an existing theme. If you want to use a custom theme for anotherapplication in the same workspace, you can copy the theme to that application by using the Copy Theme option in Shared Components. However, if the master theme (the original theme) may still require changes, you need to subscribe the copied theme to the master theme and refresh the theme whenever there are changes in the master theme. This solution guarantees that any changes to the master theme are reflected in the copied theme by using a synchronization process that updates templates and stylesheets based on their subscription status. Verified References: [Creating Themes - Oracle Help Center], [Managing Theme Subscriptions - Oracle Help Center]