Hi,

You can follow these steps:

-Select the pivot chart.
-Right-click on the horizontal axis (axis categories) and choose "Format Axis" from the context menu.
-In the Format Axis pane, under the "Axis Options" tab, find the "Text Options" section.
-Expand the "Text Options" section and click on the "Text Fill & Outline" dropdown arrow.
-Choose the desired text fill color for the axis labels.
-Click on the "Text Effects" button (represented by a capital 'A' icon) next to the "Text Fill & Outline" dropdown.
-In the "Text Effects" dialog box, go to the "Text Box" tab.
-Under the "Text Box Options" section, find the "Text Direction" dropdown and choose "Rotate all text 270°".
-Click "Close" to apply the changes and close the dialog box.
-Close the Format Axis pane.

Best Regards.