diff --git a/java-numbers-4/src/main/java/com/baeldung/number_0xff/Number0xff.java b/java-numbers-4/src/main/java/com/baeldung/number_0xff/Number0xff.java
new file mode 100644
index 0000000000..2828dccdb3
--- /dev/null
+++ b/java-numbers-4/src/main/java/com/baeldung/number_0xff/Number0xff.java
@@ -0,0 +1,20 @@
+package com.baeldung.number_0xff;
+
+public class Number0xff {
+
+    public static int getRedColor(int rgba) {
+        return rgba >> 24 & 0xff;
+    }
+
+    public static int getGreenColor(int rgba) {
+        return rgba >> 16 & 0xff;
+    }
+
+    public static int getBlueColor(int rgba) {
+        return rgba >> 8 & 0xff;
+    }
+
+    public static int getAlfa(int rgba) {
+        return rgba >> rgba & 0xff;
+    }
+}
diff --git a/java-numbers-4/src/test/java/com/baeldung/number_0xff/Number0xffUnitTest.java b/java-numbers-4/src/test/java/com/baeldung/number_0xff/Number0xffUnitTest.java
new file mode 100644
index 0000000000..6dc4d03c48
--- /dev/null
+++ b/java-numbers-4/src/test/java/com/baeldung/number_0xff/Number0xffUnitTest.java
@@ -0,0 +1,49 @@
+package com.baeldung.number_0xff;
+
+import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+
+public class Number0xffUtitTest {
+
+    @Test
+    public void test0xFFAssignedToInteger() {
+        int x = 0xff;
+        int expectedValue = 255;
+        assertEquals(x, expectedValue);
+    }
+
+    @Test
+    public void test0xFFAssignedToByte() {
+        byte y = (byte) 0xff;
+        int expectedValue = -1;
+        assertEquals(x, expectedValue);
+    }
+
+    @Test
+    public void givenColor_thenExtractRedColor() {
+        int rgba = 272214023;
+        int expectedValue = 64;
+        assertEquals(Number0xff.getRedColor(rgba), expectedValue);
+    }
+
+    @Test
+    public void givenColor_thenExtractGreenColor() {
+        int rgba = 272214023;
+        int expectedValue = 57;
+        assertEquals(Number0xff.getGreenColor(rgba), expectedValue);
+    }
+
+    @Test
+    public void givenColor_thenExtractBlueColor() {
+        int rgba = 272214023;
+        int expectedValue = 168;
+        assertEquals(Number0xff.getBlueColor(rgba), expectedValue);
+    }
+
+    @Test
+    public void givenColor_thenExtractAlfa() {
+        int rgba = 272214023;
+        int expectedValue = 7;
+        assertEquals(Number0xff.getAlfa(rgba), expectedValue);
+    }
+}
diff --git a/java-numbers-5/src/main/java/com/baeldung/Main.java b/java-numbers-5/src/main/java/com/baeldung/Main.java
deleted file mode 100644
index dfc625809d..0000000000
--- a/java-numbers-5/src/main/java/com/baeldung/Main.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package com.baeldung;
-
-public class Main {
-
-    public static void main(String[] args) {
-        int x = 0xff;
-        System.out.println(x); // output is 255
-
-        byte y = (byte) 0xff;
-        System.out.println(y); // output is -1
-
-        int rgba = 272214023;
-        int r = rgba >> 24;
-        int g = rgba >> 16 & 0xFF;
-        int b = rgba >> 8 & 0xFF;
-        int a = rgba & 0xFF;
-
-        System.out.println(r); // output is 64
-        System.out.println(g); // output is 57
-        System.out.println(b); // output is 168
-        System.out.println(a); // output is 7
-    }
-}