If you wanna know which version of the DS you have in your own DS "Phat", or DS Lite, you will need:

1. Nintendo DS "Phat" or Lite
2. Any game (GBA too)

Do the following:

1.Turn on your DS (With a game inside)
2. Enter Pictochat
3. Then enter Any of the chat rooms, either A, B, C or D
4. Get out the game that you have already inserted, the 2 screens will gain a colour (Pink in my case)

If you got:

- Black color ---> V.1
- Blue color ----> V.2
- Green color -- > V.3
- Yellow color --> V.4
- Pink color ----> V.5 (my case)

Enjoy