diff --git a/app/rgb.c b/app/rgb.c
new file mode 100644
index 0000000..55be915
--- /dev/null
+++ b/app/rgb.c
@@ -0,0 +1,89 @@
+#include "rgb.h"
+#include <FreeRTOS.h>
+#include <task.h>
+
+#include "frame.h"
+
+static TaskHandle_t rgb_handle;
+
+// Define rainbow colors in RGB565 format
+static const uint16_t rainbow_colors[] = {
+    0xF800, // Red
+    0xFC00, // Orange
+    0xFFE0, // Yellow
+    0x07E0, // Green
+    0x001F, // Blue
+    0x781F, // Indigo
+    0xF81F // Violet
+};
+
+static const size_t rainbow_colors_count = sizeof(rainbow_colors) / sizeof(rainbow_colors[0]);
+static size_t current_color_index = 0;
+static uint16_t color_background;
+static const uint8_t totalSteps = 20; // Total steps for smooth transition
+static uint8_t currentStep = 0; // Current step in the transition
+
+// Function to linearly interpolate between two colors in RGB565 format
+uint16_t
+    interpolate_color(uint16_t colorStart, uint16_t colorEnd, uint8_t step, uint8_t maxSteps) {
+    if(step >= maxSteps) return colorEnd;
+
+    int rStart = (colorStart >> 11) & 0x1F;
+    int gStart = (colorStart >> 5) & 0x3F;
+    int bStart = colorStart & 0x1F;
+
+    int rEnd = (colorEnd >> 11) & 0x1F;
+    int gEnd = (colorEnd >> 5) & 0x3F;
+    int bEnd = colorEnd & 0x1F;
+
+    int r = rStart + ((rEnd - rStart) * step / maxSteps);
+    int g = gStart + ((gEnd - gStart) * step / maxSteps);
+    int b = bStart + ((bEnd - bStart) * step / maxSteps);
+
+    return (uint16_t)((r << 11) | (g << 5) | b);
+}
+
+// Modified function to cycle through the rainbow colors for the background with smooth transitions
+void cycle_rainbow_background_colors_smooth() {
+    uint16_t currentColor = rainbow_colors[current_color_index];
+    uint16_t nextColor = rainbow_colors[(current_color_index + 1) % rainbow_colors_count];
+
+    uint16_t interpolatedColor =
+        interpolate_color(currentColor, nextColor, currentStep, totalSteps);
+    frame_set_color(interpolatedColor, color_background); // Update the background color
+
+    currentStep++;
+    if(currentStep >= totalSteps) {
+        currentStep = 0;
+        current_color_index =
+            (current_color_index + 1) % rainbow_colors_count; // Move to the next color
+    }
+}
+
+void RainbowBackgroundColorCyclerTask(void* pvParameters) {
+    const TickType_t xDelay = 50 / portTICK_PERIOD_MS; // Adjust delay for smoother transitions
+
+    while(1) {
+        cycle_rainbow_background_colors_smooth();
+        vTaskDelay(xDelay);
+    }
+}
+
+void start_rainbow_mode() {
+    if(rgb_handle) {
+        vTaskResume(rgb_handle);
+        return;
+    }
+    xTaskCreate(
+        RainbowBackgroundColorCyclerTask,
+        "RainbowBackgroundColorCycler",
+        256,
+        NULL,
+        1,
+        &rgb_handle);
+}
+
+void stop_rainbow_mode() {
+    if(rgb_handle == NULL) return;
+    vTaskSuspend(rgb_handle);
+}
diff --git a/app/rgb.h b/app/rgb.h
new file mode 100644
index 0000000..c66a89e
--- /dev/null
+++ b/app/rgb.h
@@ -0,0 +1,13 @@
+#pragma once
+
+typedef enum {
+    VgmColorModeDefault,
+    VgmColorModeCustom,
+    VgmColorModeRainbow,
+    VgmColorModeRgbBacklight,
+    VgmColorModeCount,
+} VgmColorMode;
+
+void start_rainbow_mode();
+
+void stop_rainbow_mode();
diff --git a/app/uart.c b/app/uart.c
index bcbd031..9889ca8 100644
--- a/app/uart.c
+++ b/app/uart.c
@@ -16,6 +16,7 @@
 #include "led_state.h"
 #include "bitmaps.h"
 #include "expansion_protocol.h"
+#include "rgb.h"
 
 #define UART_ID uart0
 #define UART_IRQ UART0_IRQ
@@ -374,7 +375,7 @@ static bool expansion_get_rgb_info() {
     rpc_message.command_status = PB_CommandStatus_OK;
     rpc_message.which_content = PB_Main_system_device_info_request_tag;
 
-    uint8_t color_mode = 0;
+    VgmColorMode color_mode = VgmColorModeDefault;
 
     uint32_t led_rgb_0 = 0;
     uint32_t led_rgb_1 = 0;
@@ -391,14 +392,14 @@ static bool expansion_get_rgb_info() {
             if(!expansion_is_system_device_info_rpc_response(&rpc_message)) break;
 
             if(strcmp(response->key, "hardware_vgm_color_mode") == 0)
-                color_mode = strtol(response->value, NULL, 10);
+                color_mode = (VgmColorMode)strtol(response->value, NULL, 10);
 
             if(strcmp(response->key, "hardware_screen_rgb_led0") == 0)
-                led_rgb_0 = (uint32_t)strtol(response->value, NULL, 16);
+                led_rgb_0 = strtol(response->value, NULL, 16);
             if(strcmp(response->key, "hardware_screen_rgb_led1") == 0)
-                led_rgb_1 = (uint32_t)strtol(response->value, NULL, 16);
+                led_rgb_1 = strtol(response->value, NULL, 16);
             if(strcmp(response->key, "hardware_screen_rgb_led2") == 0)
-                led_rgb_2 = (uint32_t)strtol(response->value, NULL, 16);
+                led_rgb_2 = strtol(response->value, NULL, 16);
 
             if(strcmp(response->key, "hardware_vgm_color_fg") == 0)
                 vgm_fg = strtol(response->value, NULL, 16);
@@ -410,11 +411,15 @@ static bool expansion_get_rgb_info() {
         if(rpc_message.has_next) break;
 
         switch(color_mode) {
-        case 0:
+        case VgmColorModeDefault:
             vgm_bg = 0xFC00;
             vgm_fg = 0x0000;
+            stop_rainbow_mode();
             break;
-        case 2:
+        case VgmColorModeRainbow:
+            start_rainbow_mode();
+            break;
+        case VgmColorModeRgbBacklight:
             vgm_bg = (uint16_t)((led_rgb_2 & 0xF80000) >> 8) +
                      (uint16_t)((led_rgb_2 & 0x00FC00) >> 5) +
                      (uint16_t)((led_rgb_2 & 0x0000F8) >> 3);
@@ -425,8 +430,10 @@ static bool expansion_get_rgb_info() {
                      (uint16_t)((led_rgb_0 & 0x00FC00) >> 5) +
                      (uint16_t)((led_rgb_0 & 0x0000F8) >> 3);
             vgm_fg = 0x0000;
+            stop_rainbow_mode();
             break;
         default:
+            stop_rainbow_mode();
             break;
         }