1 files changed, 26 insertions, 3 deletions
diff --git a/keyboards/ergodox/infinity/infinity.c b/keyboards/ergodox/infinity/infinity.c
index 02db67eaf2..ecc072abbe 100644
--- a/keyboards/ergodox/infinity/infinity.c
+++ b/keyboards/ergodox/infinity/infinity.c
@@ -70,10 +70,33 @@ void lcd_backlight_hal_init(void) {
     RGB_PORT->PCR[BLUE_PIN] = RGB_MODE;
 }
 
+static uint16_t cie_lightness(uint16_t v) {
+    // The CIE 1931 formula for lightness
+    // Y = luminance (output) 0-1
+    // L = lightness input 0 - 100
+
+    // Y = (L* / 902.3)           if L* <= 8
+    // Y = ((L* + 16) / 116)^3    if L* > 8
+
+    float l =  100.0f * (v / 65535.0f);
+    float y = 0.0f;
+    if (l <= 8.0f) {
+       y = l / 902.3;
+    }
+    else {
+        y = ((l + 16.0f) / 116.0f);
+        y = y * y * y;
+        if (y > 1.0f) {
+            y = 1.0f;
+        }
+    }
+    return y * 65535.0f;
+}
+
 void lcd_backlight_hal_color(uint16_t r, uint16_t g, uint16_t b) {
-	CHANNEL_RED.CnV = r;
-	CHANNEL_GREEN.CnV = g;
-	CHANNEL_BLUE.CnV = b;
+	CHANNEL_RED.CnV = cie_lightness(r);
+	CHANNEL_GREEN.CnV = cie_lightness(g);
+	CHANNEL_BLUE.CnV = cie_lightness(b);
 }
 
 __attribute__ ((weak))