Sage CRM 2023 R1 has made changing the logon screen easier and contains sample JS and CSS files that can be used as templates.
These are documented within the Release Notes and Admin Guide.
In the example below the login screen now displays an additional corporate logo.

To help System Administrators, integrators and developers understand the power of this new feature we have created an example stylesheet.

The System Administration Guide also explains how icon sets can be changed and new entirely new Themes can be designed for Sage CRM.