changed primary color usage to fix the color bug in dark mode

Changed Theme.of(context).primaryColor to Theme.of(contex).colorScheme.primary to make dark mode work properly.

lib/widgets/bank_logos.dart

@@ -1,6 +1,6 @@
 import 'package:flutter/material.dart';
 
-Widget getBankLogo(String? bankName) {
+Widget getBankLogo(String? bankName, BuildContext context) {
   if (bankName != null && bankName.toLowerCase().contains('state bank of')) {
     return Image.asset(
       'assets/images/sbi_logo.png',
@@ -72,10 +72,10 @@ Widget getBankLogo(String? bankName) {
       height: 40,
     );
   } else {
-    return const Icon(
+    return Icon(
       Icons.account_balance,
       size: 40,
-      color: Colors.grey,
+      color: Theme.of(context).colorScheme.outline,
     );
   }
 }