diff --git a/apps/hardware_test/keyboard_controller.cpp b/apps/hardware_test/keyboard_controller.cpp
index fed95e3ef..3425d0f17 100644
--- a/apps/hardware_test/keyboard_controller.cpp
+++ b/apps/hardware_test/keyboard_controller.cpp
@@ -7,7 +7,8 @@ namespace HardwareTest {
 
 KeyboardController::KeyboardController(Responder * parentResponder) :
   ViewController(parentResponder),
-  m_view(KeyboardView())
+  m_view(KeyboardView()),
+  m_color(KDColorBlack)
 {
 }
 
@@ -16,6 +17,8 @@ View * KeyboardController::view() {
 }
 
 bool KeyboardController::handleEvent(Ion::Events::Event event) {
+  Ion::LED::setColor(m_color);
+  m_color = nextColor(m_color);
   m_view.updateBatteryState(Ion::Battery::voltage(), Ion::Battery::isCharging());
   if (event != Ion::Events::Event::PlainKey(m_view.testedKey()) && event != Ion::Events::Event::ShiftKey(m_view.testedKey()) && event != Ion::Events::Event::AlphaKey(m_view.testedKey()) && event != Ion::Events::Event::ShiftAlphaKey(m_view.testedKey())) {
     m_view.setDefectiveKey(m_view.testedKey());
@@ -25,9 +28,29 @@ bool KeyboardController::handleEvent(Ion::Events::Event event) {
 }
 
 void KeyboardController::viewWillAppear() {
+  m_color = KDColorBlack;
   m_view.resetTestedKey();
   m_view.updateBatteryState(Ion::Battery::voltage(), Ion::Battery::isCharging());
 }
 
+KDColor KeyboardController::nextColor(KDColor color) {
+  if (color == KDColorBlack) {
+    return KDColorWhite;
+  }
+  if (color == KDColorWhite) {
+    return KDColorRed;
+  }
+  if (color == KDColorRed) {
+    return KDColorBlue;
+  }
+  if (color == KDColorBlue) {
+    return KDColorGreen;
+  }
+  if (color == KDColorGreen) {
+    return KDColorBlack;
+  }
+  return KDColorBlack;
+}
+
 }
 
diff --git a/apps/hardware_test/keyboard_controller.h b/apps/hardware_test/keyboard_controller.h
index 72b3bd521..ae02c1178 100644
--- a/apps/hardware_test/keyboard_controller.h
+++ b/apps/hardware_test/keyboard_controller.h
@@ -9,13 +9,13 @@ namespace HardwareTest {
 class KeyboardController : public ViewController {
 public:
   KeyboardController(Responder * parentResponder);
-
   View * view() override;
-
   bool handleEvent(Ion::Events::Event event) override;
   void viewWillAppear() override;
 private:
+  static KDColor nextColor(KDColor color);
   KeyboardView m_view;
+  KDColor m_color;
 };
 
 }
diff --git a/ion/src/simulator/Makefile b/ion/src/simulator/Makefile
index b1c3fd1f2..cbee8b017 100644
--- a/ion/src/simulator/Makefile
+++ b/ion/src/simulator/Makefile
@@ -1,6 +1,7 @@
 objs += $(addprefix ion/src/simulator/, \
   battery.o\
   init.o\
+  led.o\
 )
 
 objs += $(addprefix ion/src/simulator/boot/, main.o)
diff --git a/ion/src/simulator/led.cpp b/ion/src/simulator/led.cpp
new file mode 100644
index 000000000..a48d4ca13
--- /dev/null
+++ b/ion/src/simulator/led.cpp
@@ -0,0 +1,6 @@
+#include <ion/led.h>
+
+void Ion::LED::setColor(KDColor c) {
+}
+
+