diff --git a/app/build.gradle b/app/build.gradle
index 7a9ff61..028f841 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -1,13 +1,13 @@
 apply plugin: 'com.android.application'
 
 android {
-	compileSdkVersion 29
-	buildToolsVersion "29.0.0"
+	compileSdkVersion 30
+	buildToolsVersion "29.0.2"
 
 	defaultConfig {
 		applicationId "com.flask.colorpicker.sample"
 		minSdkVersion 14
-		targetSdkVersion 29
+		targetSdkVersion 30
 		versionCode 10
 		versionName "1.0.10"
 
diff --git a/app/src/main/res/layout/activity_sample2.xml b/app/src/main/res/layout/activity_sample2.xml
index ccae920..111c170 100644
--- a/app/src/main/res/layout/activity_sample2.xml
+++ b/app/src/main/res/layout/activity_sample2.xml
@@ -12,6 +12,7 @@
 		android:layout_height="wrap_content"
 		app:alphaSlider="true"
 		app:density="12"
+		app:minimumWheelLightness="0.01"
 		app:lightnessSlider="true"
 		app:wheelType="FLOWER"
 		app:lightnessSliderView="@+id/v_lightness_slider"
diff --git a/build.gradle b/build.gradle
index f66525b..05c4961 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,8 @@ buildscript {
 		google()
 	}
 	dependencies {
-		classpath 'com.android.tools.build:gradle:3.5.2'
+		classpath 'com.android.tools.build:gradle:7.2.2'
+		classpath "com.github.dcendents:android-maven-gradle-plugin:2.1"
 
 		// NOTE: Do not place your application dependencies here; they belong
 		// in the individual module build.gradle files
@@ -17,5 +18,6 @@ allprojects {
 	repositories {
 		jcenter()
 		google()
+		maven { url "https://jitpack.io" }
 	}
 }
diff --git a/gradle.properties b/gradle.properties
new file mode 100644
index 0000000..2d8d1e4
--- /dev/null
+++ b/gradle.properties
@@ -0,0 +1 @@
+android.useAndroidX=true
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index d17b0fe..639632b 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
-#Thu Nov 07 22:59:21 KST 2019
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.3-all.zip
 zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip
+zipStorePath=wrapper/dists
\ No newline at end of file
diff --git a/library/build.gradle b/library/build.gradle
index e290c2b..c21f5c1 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -1,12 +1,14 @@
 apply plugin: 'com.android.library'
 
+group='com.github.QuadFlask'
+
 android {
-	compileSdkVersion 29
-	buildToolsVersion "29.0.0"
+	compileSdkVersion 30
+	buildToolsVersion "29.0.2"
 
 	defaultConfig {
 		minSdkVersion 14
-		targetSdkVersion 29
+		targetSdkVersion 30
 		versionCode 17
 		versionName "0.0.15"
 	}
@@ -22,3 +24,6 @@ dependencies {
 	implementation fileTree(dir: 'libs', include: ['*.jar'])
 	implementation 'androidx.appcompat:appcompat:1.1.0'
 }
+repositories {
+	mavenCentral()
+}
diff --git a/library/src/main/java/com/flask/colorpicker/ColorPickerView.java b/library/src/main/java/com/flask/colorpicker/ColorPickerView.java
index bad746c..7efbf4f 100644
--- a/library/src/main/java/com/flask/colorpicker/ColorPickerView.java
+++ b/library/src/main/java/com/flask/colorpicker/ColorPickerView.java
@@ -43,6 +43,7 @@ public class ColorPickerView extends View {
 	private Integer initialColors[] = new Integer[]{null, null, null, null, null};
 	private int colorSelection = 0;
 	private Integer initialColor;
+	private float minimumWheelLightness;
 	private Integer pickerColorEditTextColor;
 	private Paint colorWheelFill = PaintBuilder.newPaint().color(0).build();
 	private Paint selectorStroke = PaintBuilder.newPaint().color(0).build();
@@ -108,6 +109,7 @@ private void initWith(Context context, AttributeSet attrs) {
 
 		density = typedArray.getInt(R.styleable.ColorPickerPreference_density, 10);
 		initialColor = typedArray.getInt(R.styleable.ColorPickerPreference_initialColor, 0xffffffff);
+		minimumWheelLightness = typedArray.getFloat(R.styleable.ColorPickerPreference_minimumWheelLightness, 0.0f);
 
 		pickerColorEditTextColor = typedArray.getInt(R.styleable.ColorPickerPreference_pickerColorEditTextColor, 0xffffffff);
 
@@ -188,7 +190,7 @@ private void drawColorWheel() {
 		colorWheelRenderOption.cSize = cSize;
 		colorWheelRenderOption.strokeWidth = strokeWidth;
 		colorWheelRenderOption.alpha = alpha;
-		colorWheelRenderOption.lightness = lightness;
+		colorWheelRenderOption.lightness = lightness >= minimumWheelLightness ? lightness : 1.0f;
 		colorWheelRenderOption.targetCanvas = colorWheelCanvas;
 
 		renderer.initWith(colorWheelRenderOption);
@@ -228,6 +230,7 @@ public boolean onTouchEvent(MotionEvent event) {
 			case MotionEvent.ACTION_MOVE: {
 				int lastSelectedColor = getSelectedColor();
 				currentColorCircle = findNearestByPosition(event.getX(), event.getY());
+				lightness = Utils.lightnessOfColor(currentColorCircle.getColor());
 				int selectedColor = getSelectedColor();
 
 				callOnColorChangedListeners(lastSelectedColor, selectedColor);
diff --git a/library/src/main/res/values/attrs.xml b/library/src/main/res/values/attrs.xml
index 45887f9..ab7d3d1 100644
--- a/library/src/main/res/values/attrs.xml
+++ b/library/src/main/res/values/attrs.xml
@@ -6,6 +6,7 @@
 		<attr name="border" format="boolean"/>
 		<attr name="density" format="integer"/>
 		<attr name="initialColor" format="integer"/>
+		<attr name="minimumWheelLightness" format="float"/>
 		<attr name="wheelType" format="enum">
 			<enum name="FLOWER" value="0"/>
 			<enum name="CIRCLE" value="1"/>