diff --git a/doc/Architecture.md b/doc/Architecture.md
index 6b351a73..fba16e08 100644
--- a/doc/Architecture.md
+++ b/doc/Architecture.md
@@ -123,6 +123,8 @@ This applications uses [Flutter](https://flutter.dev/) as the UI framework.
 ### Design System
 
 This application uses resources from Material Design.
+The application's Theme Data is defined in the `global_theme_data` file in the `styles` folder.
+Any other files related to the application's design system should be added to this folder.
 
 ### Localization
 
diff --git a/src/app/assets/fonts/guillon_black.ttf b/src/app/assets/fonts/guillon_black.ttf
new file mode 100644
index 00000000..1174153f
Binary files /dev/null and b/src/app/assets/fonts/guillon_black.ttf differ
diff --git a/src/app/assets/fonts/guillon_bold.ttf b/src/app/assets/fonts/guillon_bold.ttf
new file mode 100644
index 00000000..1de8d78d
Binary files /dev/null and b/src/app/assets/fonts/guillon_bold.ttf differ
diff --git a/src/app/assets/fonts/guillon_light.ttf b/src/app/assets/fonts/guillon_light.ttf
new file mode 100644
index 00000000..f2a1bef8
Binary files /dev/null and b/src/app/assets/fonts/guillon_light.ttf differ
diff --git a/src/app/assets/fonts/guillon_regular.ttf b/src/app/assets/fonts/guillon_regular.ttf
new file mode 100644
index 00000000..a7bd6b65
Binary files /dev/null and b/src/app/assets/fonts/guillon_regular.ttf differ
diff --git a/src/app/assets/fonts/guillon_semibold.ttf b/src/app/assets/fonts/guillon_semibold.ttf
new file mode 100644
index 00000000..9076c539
Binary files /dev/null and b/src/app/assets/fonts/guillon_semibold.ttf differ
diff --git a/src/app/lib/app.dart b/src/app/lib/app.dart
index f4710583..2c6c2aef 100644
--- a/src/app/lib/app.dart
+++ b/src/app/lib/app.dart
@@ -1,5 +1,6 @@
 import 'package:app/app_router.dart';
 import 'package:app/l10n/gen_l10n/app_localizations.dart';
+import 'package:app/presentation/styles/global_theme_data.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
@@ -10,6 +11,8 @@ final class App extends StatelessWidget {
   Widget build(BuildContext context) {
     return ProviderScope(
       child: MaterialApp.router(
+        theme: GlobalThemeData.lightThemeData,
+        darkTheme: GlobalThemeData.darkThemeData,
         routerConfig: router,
         localizationsDelegates: AppLocalizations.localizationsDelegates,
         supportedLocales: AppLocalizations.supportedLocales,
diff --git a/src/app/lib/presentation/styles/global_theme_data.dart b/src/app/lib/presentation/styles/global_theme_data.dart
new file mode 100644
index 00000000..b001afd0
--- /dev/null
+++ b/src/app/lib/presentation/styles/global_theme_data.dart
@@ -0,0 +1,38 @@
+import 'package:flutter/material.dart';
+
+class GlobalThemeData {
+  static ThemeData lightThemeData = themeData(lightColorScheme);
+  static ThemeData darkThemeData = themeData(darkColorScheme);
+
+  static ThemeData themeData(ColorScheme colorScheme) {
+    return ThemeData(
+      useMaterial3: true,
+      fontFamily: 'Guillon',
+      colorScheme: colorScheme,
+    );
+  }
+
+  static const ColorScheme lightColorScheme = ColorScheme(
+    primary: Color(0xFF0D59CD),
+    onPrimary: Colors.white,
+    secondary: Color(0xFF5BC5F2),
+    onSecondary: Color(0xFF001E60),
+    error: Color(0xFFD93B27),
+    onError: Color(0xFFFDEFED),
+    surface: Color(0xFFF5FAFF),
+    onSurface: Color(0xFF001E60),
+    brightness: Brightness.light,
+  );
+
+  static const ColorScheme darkColorScheme = ColorScheme(
+    primary: Color(0xFF89C5FF),
+    onPrimary: Color(0xFF121821),
+    secondary: Color(0xFFFCA58B),
+    onSecondary: Color(0xFF302B29),
+    error: Color(0xFFE8897D),
+    onError: Color(0xFF32110D),
+    surface: Color(0xFF2C3034),
+    onSurface: Colors.white,
+    brightness: Brightness.dark,
+  );
+}
diff --git a/src/app/pubspec.yaml b/src/app/pubspec.yaml
index 85f99b15..581a53e4 100644
--- a/src/app/pubspec.yaml
+++ b/src/app/pubspec.yaml
@@ -54,6 +54,25 @@ flutter:
 
   assets:
     - assets/openSourceSoftwareLicenses.json
+    - assets/fonts/guillon_black.ttf
+    - assets/fonts/guillon_bold.ttf
+    - assets/fonts/guillon_light.ttf
+    - assets/fonts/guillon_regular.ttf
+    - assets/fonts/guillon_semibold.ttf
     - .env.dev
     - .env.staging
     - .env.prod
+
+  fonts:
+    - family: Guillon
+      fonts:
+        - asset: assets/fonts/guillon_light.ttf
+          weight: 300
+        - asset: assets/fonts/guillon_regular.ttf
+          weight: 400
+        - asset: assets/fonts/guillon_semibold.ttf
+          weight: 600
+        - asset: assets/fonts/guillon_bold.ttf
+          weight: 700
+        - asset: assets/fonts/guillon_black.ttf
+          weight: 900
diff --git a/src/cli/CHANGELOG.md b/src/cli/CHANGELOG.md
index 07c8c62f..0ff0690f 100644
--- a/src/cli/CHANGELOG.md
+++ b/src/cli/CHANGELOG.md
@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 
 Prefix your items with `(Template)` if the change is about the template and not the resulting application.
 
+## 0.21.0
+- Added design system, including color scheme and fonts.
+
 ## 0.20.4
 - Updates to documentation
 
@@ -70,4 +73,4 @@ Prefix your items with `(Template)` if the change is about the template and not
 - Fixed minor bug where the current path was not being updated properly.
 - Added localization.
 - Added test for the killswitch.
-- Added integration test for forced update.
+- Added integration test for forced update.
\ No newline at end of file