Use correct primary color for bundles

aleksis/apps/lesrooster/frontend/components/timetable_management/BundleCard.vue

@@ -61,7 +61,7 @@ export default defineComponent({
       if (this.subjects.length === 1) {
         return this.subjects[0].colourFg;
       } else {
-        return "primary";
+        return this.$vuetify.theme.currentTheme.primary;
       }
     },
     colorBg() {