UX update to add thene class and apply the theme to entire app

Frontend/patient_manager/lib/theme/mihTheme.dart

@@ -0,0 +1,77 @@
+import 'package:flutter/material.dart';
+
+class MyTheme {
+  late int _mainColor;
+  late int _secondColor;
+  late int _errColor;
+  late int _succColor;
+  late int _mesColor;
+  late ThemeData data;
+
+  // Options:-
+  // f3f9d2 = Cream
+  // f0f0c9 = cream2
+  // caffd0 = light green
+  // B0F2B4 = light grean 2 *
+  // 85bda6 = light green 3
+  // 70f8ba = green
+  // F7F3EA = white
+  // a63446 = red
+
+  MyTheme() {
+    _mainColor = 0XFF3A4454;
+    _secondColor = 0XFFbedcfe;
+    _errColor = 0xffD87E8B;
+    _succColor = 0xffB0F2B4;
+    _mesColor = 0xffc8c8c8d9;
+    data = ThemeData(
+      scaffoldBackgroundColor: primaryColor(),
+      colorScheme: ColorScheme.dark(
+        primary: messageTextColor(),
+        onPrimary: primaryColor(),
+        onSurface: secondaryColor(),
+      ),
+      datePickerTheme: DatePickerThemeData(
+        backgroundColor: primaryColor(),
+
+        //------------------------------
+        cancelButtonStyle: ButtonStyle(
+          foregroundColor: WidgetStatePropertyAll(secondaryColor()),
+          overlayColor: WidgetStatePropertyAll(messageTextColor()),
+        ),
+        //------------------------------
+        confirmButtonStyle: ButtonStyle(
+          foregroundColor: WidgetStatePropertyAll(secondaryColor()),
+          overlayColor: WidgetStatePropertyAll(messageTextColor()),
+        ),
+        headerBackgroundColor: secondaryColor(),
+        headerForegroundColor: primaryColor(),
+      ),
+      appBarTheme: AppBarTheme(
+        color: secondaryColor(),
+      ),
+      floatingActionButtonTheme:
+          FloatingActionButtonThemeData(backgroundColor: secondaryColor()),
+    );
+  }
+
+  Color messageTextColor() {
+    return Color(_mesColor);
+  }
+
+  Color errorColor() {
+    return Color(_errColor);
+  }
+
+  Color successColor() {
+    return Color(_succColor);
+  }
+
+  Color primaryColor() {
+    return Color(_mainColor);
+  }
+
+  Color secondaryColor() {
+    return Color(_secondColor);
+  }
+}