refactor: add ionics color attribute to toolbars

src/app/modules/schedule/page/modal/modal-event-creator.html

@@ -13,7 +13,7 @@
   ~ this program. If not, see <https://www.gnu.org/licenses/>.
   -->
 
-<ion-toolbar>
+<ion-toolbar color="primary">
   <ion-title>{{
     'schedule.addEventModal.addEvent' | translate | titlecase
   }}</ion-title>

src/app/modules/schedule/page/schedule-page.html

@@ -14,7 +14,7 @@
   -->
 
 <ion-header>
-  <ion-toolbar>
+  <ion-toolbar color="primary">
     <ion-buttons slot="start">
       <ion-back-button></ion-back-button>
       <ion-menu-button></ion-menu-button>