Visual Changes
With Citrix Server OS 2019, the frames around active application windows shift from thick bright blue border to a thin bright blue border or will seem borderless at times. Application / Window titles and font are smaller and left-aligned.
Another visual change is how idle timeout and maintenance logoff notifications are displayed. Notifications no longer display as the prominent purple banners that span the entire screen, but as light-blue modal dialog windows in the middle of the screen and will darken any applications delivered via Citrix.