system/modules/home-manager/services/wired/default.nix

{ config, pkgs, ... }:

let
  themeCfg = config.local.themes."${config.local.theme.name}";
in
{
  services.wired = {
    enable = true;
    config = pkgs.substituteAll ({ src = ./wired.ron; } // themeCfg.notification);
  };
}