fixed dark mode issue

refilc/lib/theme/colors/utils.dart

@@ -1,4 +1,6 @@
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:refilc/models/settings.dart';
 
 class ColorsUtils {
   Color darken(Color color, {double amount = .1}) {
@@ -19,4 +21,21 @@ class ColorsUtils {
 
     return hslLight.toColor();
   }
+
+  Color fade(BuildContext context, Color color,
+      {double darkenAmount = .1, double lightenAmount = .1}) {
+    ThemeMode themeMode =
+        Provider.of<SettingsProvider>(context, listen: false).theme;
+    if (themeMode == ThemeMode.system) {
+      if (MediaQuery.of(context).platformBrightness == Brightness.dark) {
+        return lighten(color, amount: lightenAmount);
+      } else {
+        return darken(color, amount: darkenAmount);
+      }
+    } else if (themeMode == ThemeMode.dark) {
+      return lighten(color, amount: lightenAmount);
+    } else {
+      return darken(color, amount: darkenAmount);
+    }
+  }
 }