This tip shows how to convert a RGB values of a color into hexadecimal version.

 import java.awt.*;

public class Color2Hex {
  public static void main( String[] args ) {
    if (args.length != 3) {
      System.out.println("Color2Hex  r g b");
      }
   else {
      int i = Integer.parseInt(args[0]);
      int j = Integer.parseInt(args[1]);
      int k = Integer.parseInt(args[2]);
    
      Color c = new Color(i,j,k);
      System.out.println
        ( "hex: " + Integer.toHexString( c.getRGB() & 0x00ffffff ) ); 
      }
   }
}