diff --git a/src/conf.py b/src/conf.py
index cf101a8..0df0c90 100644
--- a/src/conf.py
+++ b/src/conf.py
@@ -74,6 +74,7 @@ class AppSettings(BaseSettings):
     apache_fops: list[ApacheFop] = []
     xsl_dirs: list[XslDir] = []
     pdf_projects: list[PdfProject] = []
+    theme: str | None = None
 
     model_config = SettingsConfigDict(json_file=config_path)
 
diff --git a/src/ui/MainWindow.py b/src/ui/MainWindow.py
index 99d7d6a..a2d3c88 100644
--- a/src/ui/MainWindow.py
+++ b/src/ui/MainWindow.py
@@ -57,6 +57,12 @@ class MainWindow(QMainWindow):
 
         # Theme-Menü initialisieren
         self._setup_theme_menu()
+        
+        # 
+        if (theme := app_settings.theme):
+            self.change_theme(theme)
+        else:
+            self.change_theme('Fusion')
 
         # Bilder laden
         self._load_images()
@@ -109,6 +115,8 @@ class MainWindow(QMainWindow):
                     action.setChecked(action.text() == theme_name)
 
                 print(f"Theme erfolgreich gewechselt zu: {theme_name}")
+                app_settings.theme = theme_name
+                app_settings.save()
             else:
                 print(f"Fehler: Theme '{theme_name}' konnte nicht erstellt werden")