dots/usr/share/themes/Dracula/gnome-shell/extensions/_dash-to-dock.scss

#dashtodockContainer #dash {

    background: transparent !important;

    .dash-background {
        background: $main_dark  !important;
        border: none;
    }

    .dash-item-container {

        .app-well-app,
        .show-apps {
            .overview-icon.focused .overview-icon {
                background-color: lighten($bg_color, 7%) !important;
            }
        }
    }

}