Generate random hex color in Java with source code

In this post, I will be sharing how to generate random hex color in Java with source code. Colors are represented using hexadecimal values. These hex color values are represented:

1. Always start with a pound sign (#)

2. It must contain only six digits.

3. The digits composed of a-f and 0-9.

For example, #e43fe5 is a valid hexadecimal code.

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This color representation is mostly used in HTML and websites and this code refers to the RGB color space.

Generate Random Hex color Java program code

In this program, we will use java.util package Random class to generate code:

1. We can generate random numbers by using the instance of Random class.

2. The same sequence of random numbers will be generated if two instances have the same seed value.

Now, we call the nextInt() method on that instance to generate a random number. According to Oracle docs, the parameter passed to the nextInt() method is the maximum permissible value of the generated number such that the generated value lies between 0 (inclusive) and the specified value (exclusive). In our case, the maximum value is ffffff.

import java.util.Random;

public class GenerateRandomHexColor {
  public static void main(String args[]) {
    // Create Random class object
    Random random = new Random();
    int num = random.nextInt(0xffffff + 1); 
    
    // Format num as hexadecimal string using String.format() method and print
    String hexColor = String.format("#%06x", num);
    System.out.println(hexColor);

  }
}

Output:
#1fc4c7

Point To Remember

The numbers start with the identifier 0x, which indicates that the rest of the digits are interpreted as hex.

To format the generated random number into hexadecimal color code we have used String.format() method.

We have also passed "#%06x" as an argument to the format method. In argument "#%06x", padding is indicated by character 0. By default, left padding is used and the number 6 indicates the minimum string length. Also, x indicates a hexadecimal value. Hence, we get the random hex color.

That's all for today. Please mention in the comments if you have any questions related to how to generate random hex color in Java with source code.