diff --git a/globals.js b/globals.js
index f9bf036..df9475b 100644
--- a/globals.js
+++ b/globals.js
@@ -17,6 +17,7 @@ let bRadius = 4; // 黑鍵圓角(default: 4)
 let keyAreaY = 3; // 白鍵從 Y 軸座標多少開始？(default: 3)
 let keyAreaHeight = 70; // 白鍵多高？(default: 70)
 let rainbowMode = false; // 彩虹模式 (default: false)
+let velocityMode = false; // 力度模式 (default: false)
 let cc64now = 0; // 現在的踏板狀態
 let cc67now = 0;
 
@@ -92,9 +93,9 @@ function noteOn(pitch, velocity) {
     totalIntensityScore += velocity;
     
     // piano visualizer
-    isKeyOn[pitch] = 1;
+    isKeyOn[pitch] = velocity;
     if (nowPedaling) {
-      isPedaled[pitch] = 1;
+      isPedaled[pitch] = velocity;
     }
 }
 
@@ -136,9 +137,12 @@ function toggleRainbowMode(cb) {
         select('#colorpicker').removeAttribute('disabled')
 }
 
+function toggleVelocityMode(cb) {
+    velocityMode = cb.checked;
+}
+
 function changeColor() {
-    keyOnColor = pedaledColor = color(select('#colorpicker').value());
-    darkenedColor = keyOnColor.levels.map(x => floor(x * .7));
-    pedaledColor = color(`rgb(${darkenedColor[0]}, ${darkenedColor[1]}, ${darkenedColor[2]})`)
-    console.log(pedaledColor.levels);
+    keyOnColor = color(select('#colorpicker').value());
+    let darkenedColor = keyOnColor.levels.map(x => floor(x * .7));
+    pedaledColor = color(`rgb(${darkenedColor[0]}, ${darkenedColor[1]}, ${darkenedColor[2]})`);
 }
\ No newline at end of file
diff --git a/index.html b/index.html
index 06517f1..95e2197 100644
--- a/index.html
+++ b/index.html
@@ -31,7 +31,14 @@
                         <div style="display: flex; align-items: center;">
                             <span style="margin-right: 5px;">彩虹模式</span>
                             <input type="checkbox" id="rainbow-mode-checkbox" onclick="toggleRainbowMode(this)">
-                            <label for="rainbow-mode-checkbox">
+                            <label for="rainbow-mode-checkbox" class="custom-checkbox">
+                                <span class="switch-txt" turnOn="On" turnOff="Off"></span>
+                            </label>
+                        </div>
+                        <div style="display: flex; align-items: center;">
+                            <span style="margin-right: 5px;">力度模式</span>
+                            <input type="checkbox" id="velocity-mode-checkbox" onclick="toggleVelocityMode(this)">
+                            <label for="velocity-mode-checkbox" class="custom-checkbox">
                                 <span class="switch-txt" turnOn="On" turnOff="Off"></span>
                             </label>
                         </div>
diff --git a/piano-visualizer.js b/piano-visualizer.js
index ca9b8ee..0a9a6b8 100644
--- a/piano-visualizer.js
+++ b/piano-visualizer.js
@@ -49,16 +49,28 @@ function drawWhiteKeys() {
   for (let i = 21; i < 109; i++) {
     if (isBlack[i % 12] == 0) {
       // it's a white key
-      if (isKeyOn[i] == 1 && !rainbowMode) {
-        fill(keyOnColor); // keypressed
-      } else if (isKeyOn[i] == 1 && rainbowMode) {
-        fill(map(i, 21, 108, 0, 1080) % 360, 100, 100, 100); // rainbowMode
-      } else if (isPedaled[i] == 1 && !rainbowMode) {
-        fill(pedaledColor); // pedaled
-      } else if (isPedaled[i] == 1 && rainbowMode) {
-        fill(map(i, 21, 108, 0, 1080) % 360, 100, 70, 100); // pedaled rainbowMode
+      if (velocityMode) {
+        let m = max(isKeyOn[i], isPedaled[i]) * .9 + .1;
+        if ((isKeyOn[i] || isPedaled[i]) && !rainbowMode) {
+          let whitenedColor = keyOnColor.levels.map(x => floor(x * m + 255 * (1 - m)));
+          fill(`rgb(${whitenedColor[0]}, ${whitenedColor[1]}, ${whitenedColor[2]})`); // keypressed
+        } else if ((isKeyOn[i] || isPedaled[i]) && rainbowMode) {
+          fill(map(i, 21, 108, 0, 1080) % 360, 100 * m, 100, 100); // rainbowMode
+        } else {
+          fill(0, 0, 100); // white key
+        }
       } else {
-        fill(0, 0, 100); // white key
+        if (isKeyOn[i] && !rainbowMode) {
+          fill(keyOnColor); // keypressed
+        } else if (isKeyOn[i] && rainbowMode) {
+          fill(map(i, 21, 108, 0, 1080) % 360, 100, 100, 100); // rainbowMode
+        } else if (isPedaled[i] && !rainbowMode) {
+          fill(pedaledColor); // pedaled
+        } else if (isPedaled[i] && rainbowMode) {
+          fill(map(i, 21, 108, 0, 1080) % 360, 100, 70, 100); // pedaled rainbowMode
+        } else {
+          fill(0, 0, 100); // white key
+        }
       }
       let thisX = border + wIndex * (whiteKeyWidth + whiteKeySpace);
       rect(thisX, keyAreaY, whiteKeyWidth, keyAreaHeight, radius);
@@ -80,16 +92,28 @@ function drawBlackKeys() {
 
     if (isBlack[i % 12] > 0) {
       // it's a black key
-      if (isKeyOn[i] == 1 && !rainbowMode) {
-        fill(keyOnColor); // keypressed
-      } else if (isKeyOn[i] == 1 && rainbowMode) {
-        fill(map(i, 21, 108, 0, 1080) % 360, 100, 100, 100); // rainbowMode
-      } else if (isPedaled[i] == 1 && !rainbowMode) {
-        fill(pedaledColor); // pedaled
-      } else if (isPedaled[i] == 1 && rainbowMode) {
-        fill(map(i, 21, 108, 0, 1080) % 360, 100, 70, 100); // pedaled rainbowMode
+      if (velocityMode) {
+        let m = max(isKeyOn[i], isPedaled[i]) * .9 + .1;
+        if ((isKeyOn[i] || isPedaled[i]) && !rainbowMode) {
+          let darkenedColor = keyOnColor.levels.map(x => floor(x * m));
+          fill(`rgb(${darkenedColor[0]}, ${darkenedColor[1]}, ${darkenedColor[2]})`); // keypressed
+        } else if ((isKeyOn[i] || isPedaled[i]) && rainbowMode) {
+          fill(map(i, 21, 108, 0, 1080) % 360, 100, 100 * m, 100); // rainbowMode
+        } else {
+          fill(0, 0, 0); // black key
+        }
       } else {
-        fill(0, 0, 0); // white key
+        if (isKeyOn[i] && !rainbowMode) {
+          fill(keyOnColor); // keypressed
+        } else if (isKeyOn[i] && rainbowMode) {
+          fill(map(i, 21, 108, 0, 1080) % 360, 100, 100, 100); // rainbowMode
+        } else if (isPedaled[i] && !rainbowMode) {
+          fill(pedaledColor); // pedaled
+        } else if (isPedaled[i] && rainbowMode) {
+          fill(map(i, 21, 108, 0, 1080) % 360, 100, 70, 100); // pedaled rainbowMode
+        } else {
+          fill(0, 0, 0); // black key
+        }
       }
 
       let thisX = border + (wIndex - 1) * (whiteKeyWidth + whiteKeySpace) + isBlack[i % 12];
@@ -147,7 +171,7 @@ function pushHistories() {
   shortTermTotal.push(notesThisFrame);
   shortTermTotal.shift();
   notesThisFrame = 0;
-  legatoHistory.push(isKeyOn.reduce((accumulator, currentValue) => accumulator + currentValue, 0));
+  legatoHistory.push(isKeyOn.reduce((accumulator, currentValue) => accumulator + !!currentValue, 0));
   legatoHistory.shift();
 
 
@@ -183,8 +207,7 @@ function getPressedKeys(returnString = true) {
   let pressedOrPedaled = [];
 
   for (let i = 0; i < isKeyOn.length; i++) {
-    pressedOrPedaled[i] = isKeyOn[i] === 1 || isPedaled[i] === 1 ? 1 : 0;
-
+    pressedOrPedaled[i] = isKeyOn[i] || isPedaled[i];
   }
 
   let noteNames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']; // default if sharp
@@ -196,7 +219,7 @@ function getPressedKeys(returnString = true) {
   const pressedKeys = [];
 
   for (let i = 0; i < pressedOrPedaled.length; i++) {
-    if (pressedOrPedaled[i] === 1) {
+    if (pressedOrPedaled[i]) {
       const noteName = noteNames[i % 12];
       const octave = Math.floor(i / 12) - 1;
       pressedKeys.push(`${noteName}${octave}`);
diff --git a/style.css b/style.css
index d6a410b..b000fc6 100644
--- a/style.css
+++ b/style.css
@@ -552,7 +552,7 @@ input[type=checkbox] {
     visibility: hidden;
 }
 
-label[for=rainbow-mode-checkbox] {
+label.custom-checkbox {
     cursor: pointer;
     width: 50px;
     height: 25px;
@@ -563,7 +563,7 @@ label[for=rainbow-mode-checkbox] {
     transition: .3s;
 }
 
-label[for=rainbow-mode-checkbox]:after {
+label.custom-checkbox:after {
     content: '';
     position: absolute;
     top: 1.25px;
@@ -575,15 +575,15 @@ label[for=rainbow-mode-checkbox]:after {
     transition: .3s;
 }
 
-input:checked + label[for=rainbow-mode-checkbox] {
+input:checked + label.custom-checkbox {
 	background: #6f42c1;
 }
 
-label[for=rainbow-mode-checkbox]:active:after {
+label.custom-checkbox:active:after {
 	width: 32.5px;
 }
 
-input:checked + label[for=rainbow-mode-checkbox]:after {
+input:checked + label.custom-checkbox:after {
 	left: calc(100% - 1.25px);
 	transform: translateX(-100%);
 }
\ No newline at end of file