A theme determines how the JasperReports Server interface appears to users. Administrator can create and set different themes for each organization. To set a theme through web services, use the PUT method of the REST v2/organizations service to modify the corresponding property of the desired organization.

For example:

PUT http://localhost:8080/jasperserver-pro/rest_v2/organizations/Audit

For more information about themes, see the JasperReports Server Administrator Guide.