By default, when creating new Pivot Tables in Excel, the table has a mostly white design.
However, there are multiple color designs available that can assist in producing functional and readable Pivot Tables.
To access the report layout option, in the toolbar select the Design tab:
With the Pivot Table selected, you can click any of the Style images shown to modify the design. You can use the arrows to the right of the Styles to look through all additional options.
Here's an example of the base style versus additional options, viewing a report by service date of patient claims with procedure codes: