More appearance options to allow for branded self-hosted installs

Description

Currently the appearance settings allow us to upload a logo, set a title, and description. However, for those of us with corporate logos that have colors similar to the purple header, we must upload a "light" or "white" version of our logo. But then the logo doesn't appear nicely in emails. Additionally, there's no longer a way to override the "GitLab" title in the header even though we have a title set in the appearance settings.

Proposal

Allow for more appearance settings to control the look and feel of Gitlab so that we can match our company branding.

  • Allow for header color to be changed
  • Allow for header title to be set to the title in appearance settings
  • Allow for separate header and email logo uploads. Default to the header logo in emails if no email logo is provided.

Use cases

As an admin of self-hosted EES+, I'd like to brand Gitlab to match my companies brand.

Feature checklist