Application Colors are just what they “describe”: colours for the UI and other elements alien to your document. Colours (and many other attributes) for YOUR data is controlled by styles. But if you applied manually some attribute/property over your data, this overrides styles. Consequently, to achieve what you’re looking for requires that your spreadsheet has been carefully prepared. Id est, “decoration” must be considered as essential as data itself. Once “decoration” is styled, it can be modified centrally by modifying the style. And you can collect all your customisation in a special file called a template (and make this template the default one). Therefore, changing the styles in the template will automatically apply to all spreadsheets based on this template (once again, provided you didn’t overload with direct formatting).