diff --git a/color-module/src/lib.rs b/color-module/src/lib.rs
index b2f407c..afbde93 100644
--- a/color-module/src/lib.rs
+++ b/color-module/src/lib.rs
@@ -15,6 +15,7 @@ use wasm_bindgen::prelude::*;
 mod color_card;
 mod color_differ;
 mod errors;
+mod reversing;
 
 #[wasm_bindgen]
 pub fn represent_rgb(color: &str) -> Result<Box<[u8]>, errors::ColorError> {
@@ -496,3 +497,37 @@ pub fn differ_in_oklch(
     );
     Ok(oklch.difference(&other_oklch))
 }
+
+#[wasm_bindgen]
+pub fn tint_scale(
+    basic_color: &str,
+    mixed_color: &str,
+) -> Result<reversing::MixReversing, errors::ColorError> {
+    let basic_color = Srgb::from_str(basic_color)
+        .map_err(|_| errors::ColorError::UnrecogniazedRGB(basic_color.to_string()))?
+        .into_format::<f32>();
+    let mixed_color = Srgb::from_str(mixed_color)
+        .map_err(|_| errors::ColorError::UnrecogniazedRGB(mixed_color.to_string()))?
+        .into_format::<f32>();
+    Ok(reversing::MixReversing::from_tint_rgb(
+        basic_color,
+        mixed_color,
+    ))
+}
+
+#[wasm_bindgen]
+pub fn shade_scale(
+    basic_color: &str,
+    mixed_color: &str,
+) -> Result<reversing::MixReversing, errors::ColorError> {
+    let basic_color = Srgb::from_str(basic_color)
+        .map_err(|_| errors::ColorError::UnrecogniazedRGB(basic_color.to_string()))?
+        .into_format::<f32>();
+    let mixed_color = Srgb::from_str(mixed_color)
+        .map_err(|_| errors::ColorError::UnrecogniazedRGB(mixed_color.to_string()))?
+        .into_format::<f32>();
+    Ok(reversing::MixReversing::from_shade_rgb(
+        basic_color,
+        mixed_color,
+    ))
+}
diff --git a/color-module/src/reversing.rs b/color-module/src/reversing.rs
new file mode 100644
index 0000000..c9e364f
--- /dev/null
+++ b/color-module/src/reversing.rs
@@ -0,0 +1,42 @@
+use palette::rgb::Rgb;
+use serde::Serialize;
+use wasm_bindgen::prelude::wasm_bindgen;
+
+#[derive(Debug, Clone, Copy, Serialize)]
+#[wasm_bindgen]
+pub struct MixReversing {
+    pub r_factor: f32,
+    pub g_factor: f32,
+    pub b_factor: f32,
+    pub average: f32,
+}
+
+impl MixReversing {
+    pub fn from_tint_rgb(basic_color: Rgb, mixed_result: Rgb) -> Self {
+        let r_factor = (mixed_result.red - basic_color.red) / (1.0 - basic_color.red);
+        let g_factor = (mixed_result.green - basic_color.green) / (1.0 - basic_color.green);
+        let b_factor = (mixed_result.blue - basic_color.blue) / (1.0 - basic_color.blue);
+        let average = (r_factor + g_factor + b_factor) / 3.0;
+
+        MixReversing {
+            r_factor,
+            g_factor,
+            b_factor,
+            average,
+        }
+    }
+
+    pub fn from_shade_rgb(basic_color: Rgb, mixed_result: Rgb) -> Self {
+        let r_factor = (basic_color.red - mixed_result.red) / (0.0 - basic_color.red);
+        let g_factor = (basic_color.green - mixed_result.green) / (0.0 - basic_color.green);
+        let b_factor = (basic_color.blue - mixed_result.blue) / (0.0 - basic_color.blue);
+        let average = (r_factor + g_factor + b_factor) / 3.0;
+
+        MixReversing {
+            r_factor,
+            g_factor,
+            b_factor,
+            average,
+        }
+    }
+}