Update color palette and styles across components for improved visual consistency

- Changed theme color in index.html to a brighter orange for better aesthetics.
- Introduced a modern color palette in styles.scss for enhanced readability and consistency.
- Updated various components (AppFooter, AppNavigation, DialogWidget, etc.) to utilize new color variables, ensuring a cohesive look throughout the application.
- Adjusted button styles and hover effects for improved user interaction feedback.
- Enhanced background colors and text colors for better contrast and visibility.

frontend/src/components/DialogWidget.vue

@@ -216,7 +216,7 @@ export default {
   justify-content: space-between;
   padding: 5px 5px;
   border-bottom: 1px solid #ddd;
-  background-color: #F9A22C;
+  background-color: #FF6B35;
   cursor: move;
 }
 
@@ -258,7 +258,7 @@ dialog-footer {
   margin-left: 10px;
   padding: 5px 10px;
   cursor: pointer;
-  background: #F9A22C;
+  background: #FF6B35;
   color: #000000;
   border: none;
   border-radius: 4px;
@@ -266,9 +266,9 @@ dialog-footer {
 }
 
 .dialog-button:hover {
-  background: #fdf1db;
-  color: #7E471B;
-  border: 1px solid #7E471B;
+  background: #FFF4F0;
+  color: #5D4037;
+  border: 1px solid #5D4037;
 }
 
 .is-active {