Pokemon Emerald Cheats

Every time you encounter a pokemon you have a 1/8192 chance of the pokemon being a different color, this is called a shiny pokemon

To get the other Lati (Latios or Latias), Mix Records with a Pokemon Ruby/Sapphire game that used the Eon Ticket. You can then get to a hidden island via the SS Tidal where you can find the Lati you didn't choose.

After you defeat the Elite Four, go to your house and watch the television downstairs. After you watch it, your mom will ask you what color the Pokemon is. If you say Red, you will find Latias. If you say Blue, it will be Latios.