Power BI Report Themes is a feature that allows you to apply multiple settings to a report at the same time and share them via a single JSON file. Check out this page for more information: Report Themes with Custom Visuals
Assuming you are setting up a custom JSON theme file (as described here), the customizable properties of Calendar Pro are:
| Property | Theme Color |
|---|---|
| Cells border color | foregroundNeutralDark |
| Events label border color | foregroundNeutralDark |
| Group title color | foregroundNeutralSecondaryAlt |
| Legend color | foreground |
| Week axis color | foregroundNeutralSecondaryAlt |
| Weekday axis color | foregroundNeutralSecondaryAlt |
| Year axis color | foregroundNeutralSecondaryAlt |