Within the old admin center there used to be an options COMPANY PROFILE
Within the Company profile there were a few option available to the Global Administrator
Recently I upgraded to the new look admin center and the closest thing similar to the company profile option is organization profile.
The options for Custom Theming, Custom Tiles and Custom Helpdesk have now disappeared.
I got a response from Microsoft on Yammer:
We’re in the process of adding this feature to the new admin center. Expect it to be available in the coming weeks.