fix(core): update

ts/domtools.classes.thememanager.ts

@@ -32,6 +32,7 @@ export class ThemeManager {
   }
 
   private async updateAllConnectedElements() {
+    document.body.style.background = this.goBrightBoolean ? '#fff' : '#000';
     this.domtoolsRef.elementInstrumenter.forEachelement(async elementArg => {
       await this.setThemeStatusForElement(elementArg, this.goBrightBoolean);
     });