Add color constants

Go to the file /app/src/config/color_constants.dart:

import 'dart:ui';
import 'package:flutter/material.dart';

Color hexToColor(String hex) {
  assert(RegExp(r'^#([0-9a-fA-F]{6})|([0-9a-fA-F]{8})$').hasMatch(hex),
      'hex color must be #rrggbb or #rrggbbaa');

  return Color(
    int.parse(hex.substring(1), radix: 16) +
        (hex.length == 7 ? 0xff000000 : 0x00000000),
  );
}

class ColorConstants {
  static Color lightScaffoldBackgroundColor = hexToColor('#F9F9F9');
  static Color darkScaffoldBackgroundColor = hexToColor('#2F2E2E');
  static Color secondaryAppColor = hexToColor('#5E92F3');
  static Color secondaryDarkAppColor = Colors.white;
}

You can use it in a widget as shown below:

Container(
  color: ColorConstants.lightBackground,
),