Flutter – how to make SliverAppBar color the background

I’m building a Flutter app and when I try to use SliverAppBar it does not apply background color to all screen’s top, like in the image.

The edges of the clock and network are not in blue.

What am I missing in my code?

return SliverAppBar(
      pinned: widget.isPinAppBar,
      snap: false,
      floating: false,
      titleSpacing: 0,
      elevation: 0,
      forceElevated: true,
      backgroundColor: HexColor('2400ff'),
          // Theme.of(context).colorScheme.background.withOpacity(config.opacity),
      title: PreviewOverlay(
          index: 0,
          config: logoConfig as Map<String, dynamic>?,
          builder: (value) {
            final appModel = Provider.of<AppModel>(context, listen: true);
            return Selector<CartModel, int>(
              selector: (_, cartModel) => cartModel.totalCartQuantity,
              builder: (context, totalCart, child) {
                return Selector<NotificationModel, int>(
                  selector: (context, notificationModel) =>
                      notificationModel.unreadCount,
                  builder: (context, unreadCount, child) {
                    return Logo(
                      config: config,
                      logo: appModel.themeConfig.logo,
                      notificationCount: unreadCount,
                      totalCart: totalCart,
                      onSearch: () {
                        FluxNavigate.pushNamed(RouteList.homeSearch);
                      },
                      onCheckout: () {
                        FluxNavigate.pushNamed(RouteList.cart);
                      },
                      onTapNotifications: () {
                        FluxNavigate.pushNamed(RouteList.notify);
                      },
                      onTapDrawerMenu: () =>
                          NavigateTools.onTapOpenDrawerMenu(context),
                    );
                  },
                );
              },
            );
          }),
    );