Bug#1105056: gdm3: coordinate accent colour with ceratopsian theme for trixie?

[Simon McVittie <smcv@debian.org>]

Package: gdm3
Version: 48.0-1
Severity: wishlist
X-Debbugs-Cc: debian-desktop@lists.debian.org
Tags: trixie sid

While reporting a separate bug about the Debian logo shown at the gdm 
login prompt having poor contrast, I noticed that the accent colour 
(org/gnome/desktop/interface/accent-color in dconf-editor, Appearance -> 
Accent Colour in gnome-control-center) is one feature of the gdm login 
prompt that we can easily tweak if we want to. Should we?

It's chosen from a limited palette of presets rather than being 
arbitrarily configurable, but the "teal" and "slate" choices look 
vaguely similar to the Ceratopsian theme. For example we could set up 
the default /etc/gdm3/greeter.dconf-defaults to include these 
uncommented lines:

    [org/gnome/desktop/interface]
    accent-color='teal'

This affects the highlights in the System and Accessibility menus (top 
right corner), the highlight on today's date in the calendar, the focus 
rectangle around the selected user, and the focus rectangle around other 
active widgets like the password entry box, replacing the default 
sky blue:

https://people.debian.org/~smcv/temp/2025/trixie-branding/teal-accent.png

    smcv