Well, until we handle it properly in Customers/users should be able to replace Elastic logo and customize Kibana themes through advanced setting · Issue #75377 · elastic/kibana · GitHub it's all unsupported and can change from version to version, but as a temporary workaround you can try to change these places in Kibana code:
- Top logo, you can change
iconType
property to something like thisiconType={"https://some-host/some-picture.png"}
- Login page, you can change
type
property to something like thistype={"https://some-host/some-picture.png"}
Unfortunately it's not possible to do via pure CSS.
Hope that helps.
Best,
Oleg