First, you have to trade your Pokemon Colosseum with Ruby/Sapphire (And I think Leafgreen/Firered too) Once you do that, you have to get the Pokemon to leafgreen/firered, and then migrate them to Pokemon diamond/pearl.
For this though, you have to had beaten the games.
if you can connect colosseum to a gba, then trade the Pokemon to the gba game and migrate!
Migrate from fire red leafgreen emerald or colosseum
Special: Migrate from FireRed, LeafGreen, or Colosseum. (Unobtainable in Diamond and Pearl.)
You can't find a Misdreavus in Pokémon Diamond. You'll have to trade it from Pokémon Pearl or migrate it from Pokémon LeafGreen or Colosseum.
You can't trade directly to Pokemon Colosseum. You need a GBA and a 3rd generation game (Emerald, FireRed, LeafGreen, etc.) and the GBA adapter cable to connect with the Gamecube. You can trade to there and then migrate the Pokemon to your Diamond.
Migrate from FireRed, LeafGreen, or Colosseum. (Unobtainable in Diamond and Pearl.)
You cannot catch the legendary dogs in Diamond or Pearl, you must migrate from Pokemon LeafGreen, FireRed, Colosseum, or XD.
you need to beat the E4
migrate. totally migrate.
If you have the Pokemon Diamond Version booklet go to the content page and look up how to migrate .
you have to have Pokemon ruby to migrate it
You have to migrate the Pokemon from emerald.