Joining strings (n00b)

Hello gurus :)
Need some help here. Don't know anything about programming and google pointed me here :) Heres my story. I found a really old password protected file. I remember that I used certain words but have forgot the capitalization. So I need a custom made dictionary to crack it open.
I know that my password is a combination of 3 words repeated twice. Lets say its a cat, blue and three numbers/characters eg bluecat666BLUECAT&&& or BlueCat666bLuEcAt666

I made (my first ever) arrays and added all the combinations
:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string[] cat = { "cat", "caT", "cAt", "cAT", "Cat", "CaT","CAt","CAT"};
string[] blue = { "blue", "bluE", "blUe", "blUE", "bLue", "bLuE", "bLUe", "bLUE", "Blue", "BluE", "BlUe", "BlUE", "BLue", "BLuE", "BLUe","BLUE"};
string[] num = { "666", "&&&"};
}
}
}

How can I join them and output all the combinations to a text file ? Its something to do with for loop and cat[i]+blue[i]+num[i]+cat[i]+blue[i]+num[i] but thats way over my head.


Thank you so much !

perhaps something like the following ...

Code:

---

            using (StreamWriter writer = new StreamWriter("C:\\256Combinations.txt")) {
                foreach (string cat in cats)
                    foreach (string color in spectrum)
                        foreach (string other in num)
                            writer.WriteLine(cat + color + other);
            }// end using StreamWriter 'writer'

---

I have no idea what you just wrote :D
what is streamwriter ? and where does "spectrum" appear from ?

OMG it actually works !
This is some sort of black magic :D thank you !