Update AppearanceViewController.swift

Clocker/Preferences/Appearance/AppearanceViewController.swift

@@ -63,6 +63,20 @@ class AppearanceViewController: ParentViewController {
             "7 days",
         ])
         
+        theme.removeAllItems()
+        theme.addItems(withTitles: [
+            "Light",
+            "Dark",
+            "System",
+            "Solarized Light"
+        ])
+        
+        if #available(macOS 11.0, *) {
+            
+        } else {
+            theme.font = NSFont.systemFont(ofSize: 13)
+        }
+
         setup()
 
         themeDidChangeNotification = NotificationCenter.default.addObserver(forName: .themeDidChangeNotification, object: nil, queue: OperationQueue.main) { _ in