Introduce an accent color preference across the app: add a settings UI input (with restart note), persist it to AppState and config (read/write), and accept it in save_settings. Integrate the value into theming: compute a semi-transparent selection color, apply it to table selection styles, and pass it to qdarktheme as the primary color (including when window transparency is enabled). Also apply the accent to the tracker combo selection styling as a UI polish.
Vxrtrauter