Remember, you create applications for users!
Oracle APEX applications are usually created for business purposes – for data browsing, editing and analysing.
Developers of APEX applications focus mainly on the essential functionality, pushing the appearance of the application into the background.
This is a strategic mistake!
Functionality and appearance of an application should always go hand in hand. Applications that work well but look clumsy are considered poor by the users. In such a case, any changes in forms, processes or validations are of no use – a good theme is the only solution.