If you wish to change the branding of the login screen then head over to the Azure Portal and under “Users and Groups” go to “Company Branding”.
You must create a few images in the correct size and format and then upload them to the portal:
- Sign-in Background: 1920x1080px
- Banner Logo: 280x60px
- Square Logo 240x240px
Once saved your users will now see the new branded login screen after they have entered their email address, this applies to both the old and new style login screens:
I need to re-work the background image still, but the concept works for now.