diff --git a/analog_system_monitor_arduino/Core.cpp b/analog_system_monitor_arduino/Core.cpp
index e813730..e65087a 100644
--- a/analog_system_monitor_arduino/Core.cpp
+++ b/analog_system_monitor_arduino/Core.cpp
@@ -1,5 +1,6 @@
 #include <Arduino.h>
 #include "Core.h"
+#include <FastLED.h>
 
 WiFiUDP udp;
 Preferences prefs;
@@ -26,6 +27,13 @@ float calibratedPoints[NUM_CHANNELS][5] = {
   {0.0f, 26.0f, 50.0f, 76.0f, 99.0f}
 };
 
+// -------------------------------
+// Lighting (FastLED)
+// -------------------------------
+#define LED_PIN 23
+#define NUM_LEDS 20   // or more if you expand later
+CRGB leds[NUM_LEDS];
+
 uint8_t lightingHue = 0;
 uint8_t lightingSaturation = 255;
 uint8_t lightingBrightness = 255;
@@ -63,6 +71,17 @@ float applyCalibration(uint8_t ch, float logicalDuty) {
   return calibratedPoints[ch][4];
 }
 
+void applyLighting() {
+    // Convert HSV (0–255 each) to RGB
+    CHSV hsv(lightingHue, lightingSaturation, lightingBrightness);
+
+    for (int i = 0; i < NUM_LEDS; i++) {
+        leds[i] = hsv;
+    }
+
+    FastLED.show();
+}
+
 void updateConnectionStatusUI(ConnectionState state) {
     const char* text = "Unknown";
 
@@ -118,6 +137,12 @@ void coreInit() {
   Serial.printf("Lighting loaded (0–255): H=%d S=%d B=%d\n",
                 lightingHue, lightingSaturation, lightingBrightness);
 
+  // FastLED init
+  FastLED.addLeds<WS2812B, LED_PIN, GRB>(leds, NUM_LEDS);
+  FastLED.setBrightness(255);  // full brightness; HSV V controls actual output
+
+  // Apply lighting immediately at boot
+  applyLighting();
 
   // Start UDP with runtime port
   udp.begin(udpPort);
diff --git a/analog_system_monitor_arduino/Core.h b/analog_system_monitor_arduino/Core.h
index 747d0e7..9c3a419 100644
--- a/analog_system_monitor_arduino/Core.h
+++ b/analog_system_monitor_arduino/Core.h
@@ -48,3 +48,4 @@ void coreUpdateState();   // called from loop()
 // Helpers used by UI
 float applyCalibration(uint8_t ch, float logicalDuty);
 void updateConnectionStatusUI(ConnectionState state);
+void applyLighting();
diff --git a/analog_system_monitor_arduino/Ui.cpp b/analog_system_monitor_arduino/Ui.cpp
index 69961e9..33473b3 100644
--- a/analog_system_monitor_arduino/Ui.cpp
+++ b/analog_system_monitor_arduino/Ui.cpp
@@ -246,6 +246,7 @@ void uiInit(uint16_t& tabSettings, uint16_t& tabLighting, uint16_t& tabCalibrati
           int sliderVal = sender->value.toInt(); // 0–100
           lightingHue = fromSlider(sliderVal); // convert to 0–255
           Serial.printf("Lighting Hue changed (RAM only): %d\n", lightingHue);
+          applyLighting();
       }
   );
 
@@ -260,6 +261,7 @@ void uiInit(uint16_t& tabSettings, uint16_t& tabLighting, uint16_t& tabCalibrati
           int sliderVal = sender->value.toInt(); // 0–100
           lightingSaturation = fromSlider(sliderVal);
           Serial.printf("Lighting Saturation updated (RAM only): %d\n", lightingSaturation);
+          applyLighting();
       }
   );
 
@@ -274,6 +276,7 @@ void uiInit(uint16_t& tabSettings, uint16_t& tabLighting, uint16_t& tabCalibrati
           int sliderVal = sender->value.toInt(); // 0–100
           lightingBrightness = fromSlider(sliderVal);
           Serial.printf("Lighting Brightness updated (RAM only): %d\n", lightingBrightness);
+          applyLighting();
       }
   );
   ESPUI.addControl(