You can adjust the theme by setting the UCR variable "saml/idp/lookandfeel/theme".
The default theme is "univentiontheme:univention" which is located here:
Be aware, that we have plans to include the login page directly in UMC via an iframe so that custom themes might need manual adaptions in the future:
forge.univention.org/bugzilla/s ... i?id=39459
The FQDN might be changed via the UMC module 'SAML Identity Provider' by opening the service provider enty and inserting a new name into "Name of the organization for this service provider".
Or via CLI:
udm saml/serviceprovider modify --dn 'SAMLServiceProviderIdentifier=https://foo.example.com/univention-management-console/saml/metadata,cn=saml-serviceprovider,cn=foo,dc=example,dc=com' --set serviceProviderOrganizationName='Whatever you want!'
Note: this might get overridden when installing UCS release updates!