🐛 Weird animation and transition inconsistencies when switching accent color and theme mode

**Describe the bug**
The animation when the theme accent color or theme mode are changed is inconsistent across widgets. Some take longer to reflect the transition.

**To Reproduce**
Steps to reproduce the behavior:
1. On the example app, go to "Settings"
2. Scroll down to 'Accent Color'
3. Change the accent color

**Expected behavior**
The animation is solid, smooth and straightforward in all widgets.

**Screenshots**

https://github.com/user-attachments/assets/2c2e6687-91ed-4e23-b5fb-7d1c9d52a0b2

https://github.com/user-attachments/assets/b0164c0d-c74d-406e-b444-528f95af5c85

https://github.com/user-attachments/assets/5a6a816b-d7e2-4576-9cb5-fea46c6854c1

**Additional context**
n/a

Reproduce the issue in the example app by opening Settings and changing Accent Color, then compare the affected widgets and their theme-mode transitions. Trace the widget code responsible for those animations and identify why their timing differs. Done means accent-color and theme-mode changes animate smoothly and consistently across the affected widgets.

Written by the indexing model from the issue text.