diff --git a/app/src/rgb_underglow.c b/app/src/rgb_underglow.c
index 5f38aba7..983dcc40 100644
--- a/app/src/rgb_underglow.c
+++ b/app/src/rgb_underglow.c
@@ -25,8 +25,11 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 #define STRIP_NUM_PIXELS DT_PROP(DT_CHOSEN(zmk_underglow), chain_length)
 
 #define HUE_MAX 360
-#define SAT_MAX 100
-#define BRT_MAX 100
+#define SAT_MAX 101
+#define BRT_MAX 101
+#define RGB_MAX 255
+#define NUM_SEG 6                   // Number of segments on color wheel
+#define DEG_SEG (HUE_MAX / NUM_SEG) // degrees per color wheel segment
 
 enum rgb_underglow_effect {
     UNDERGLOW_EFFECT_SOLID,
@@ -54,6 +57,7 @@ static struct rgb_underglow_state state;
 static const struct device *ext_power;
 #endif
 
+#if IS_ENABLED(CONFIG_FPU)
 static struct led_rgb hsb_to_rgb(struct zmk_led_hsb hsb) {
     double r, g, b;
 
@@ -102,6 +106,53 @@ static struct led_rgb hsb_to_rgb(struct zmk_led_hsb hsb) {
 
     return rgb;
 }
+#else
+static struct led_rgb hsb_to_rgb(struct zmk_led_hsb hsb) {
+    uint8_t i = hsb.h / DEG_SEG;
+    uint8_t f = hsb.h % DEG_SEG;
+    uint8_t v = hsb.b * RGB_MAX / BRT_MAX;
+    uint8_t p = hsb.b * RGB_MAX * (SAT_MAX - hsb.s) / SAT_MAX / BRT_MAX;
+    uint8_t q = hsb.b * RGB_MAX * (SAT_MAX * DEG_SEG - f * hsb.s) / SAT_MAX / DEG_SEG / BRT_MAX;
+    uint8_t t =
+        hsb.b * RGB_MAX * (SAT_MAX * DEG_SEG - (DEG_SEG - f) * hsb.s) / SAT_MAX / DEG_SEG / BRT_MAX;
+    struct led_rgb rgb;
+
+    switch (i) {
+    case 0:
+        rgb.r = v;
+        rgb.g = t;
+        rgb.b = p;
+        break;
+    case 1:
+        rgb.r = q;
+        rgb.g = v;
+        rgb.b = p;
+        break;
+    case 2:
+        rgb.r = p;
+        rgb.g = v;
+        rgb.b = t;
+        break;
+    case 3:
+        rgb.r = p;
+        rgb.g = q;
+        rgb.b = v;
+        break;
+    case 4:
+        rgb.r = t;
+        rgb.g = p;
+        rgb.b = v;
+        break;
+    case 5:
+        rgb.r = v;
+        rgb.g = p;
+        rgb.b = q;
+        break;
+    }
+
+    return rgb;
+}
+#endif
 
 static void zmk_rgb_underglow_effect_solid() {
     for (int i = 0; i < STRIP_NUM_PIXELS; i++) {