Update color scheme across components to use new primary orange variable

- Replaced hardcoded orange color values with the new CSS variable for primary orange in multiple components, ensuring consistency in styling.
- Updated styles in DialogWidget, MessageboxWidget, SettingsWidget, SimpleTabs, and various Falukant components to enhance maintainability and readability.

frontend/src/components/SimpleTabs.vue

@@ -57,7 +57,7 @@ export default {
 }
 
 .simple-tab.active {
-  background: #FF6B35;
+  background: var(--color-primary-orange);
   color: #000;
 }
 </style>