some little stuff

lib/homepage.dart

@@ -29,7 +29,7 @@ class _HomePageState extends State<HomePage> {
             backgroundColor: color,
             color: Colors.white,
             activeColor: Colors.white,
-            tabBackgroundColor: Colors.grey,
+            tabBackgroundColor: ligten(color),
             gap: 8,
             padding: EdgeInsets.all(16),
             tabs: [
@@ -57,4 +57,23 @@ class _HomePageState extends State<HomePage> {
       ),
     );
   }
+
+  Color darken(Color color, [double amount = .1]) {
+    assert(amount >= 0 && amount <= 1);
+
+    final hsl = HSLColor.fromColor(color);
+    final hslDark = hsl.withLightness((hsl.lightness - amount).clamp(0.0, 1.0));
+
+    return hslDark.toColor();
+  }
+
+  Color ligten(Color color, [double amount = .1]) {
+    assert(amount >= 0 && amount <= 1);
+
+    final hsl = HSLColor.fromColor(color);
+    final hslLight =
+        hsl.withLightness((hsl.lightness + amount).clamp(0.0, 1.0));
+
+    return hslLight.toColor();
+  }
 }