gistfile1.java

    public void rainbowize(CommandSender sender, String[] args){
        for(String y : args){
            String colorMessage = appendColors(y);
            sender.sendMessage(colorMessage);
        }      
    }

    private String appendColors(String y) {
        y.trim();
        StringBuilder sb = new StringBuilder(y);
        for(int x = 0; x < y.length(); x++){
            sb.append(getRandomColor());
        }
      return sb.toString();
    }
    
    private ChatColor getRandomColor(){
        Random rdm = new Random();
        int zz = rdm.nextInt(12);
        ChatColor randomColor = ChatColor.getByCode(zz);
        return randomColor;
    }
}