How many emblems do you need to get a brown egg in sonic adventure 2 battle

You need 30 emblems in order for a Brown Egg to to be able to be for sale in the Black Market. However, keep in mind that no matter how many emblems you have, one or two egg colors may never appear in the Black Market. Depending on your Chao Garden saved file, the rarity of what eggs appear in you Black Market may differ, and certain colors may never appear at all. If a color you are looking for has never appeared in the Black Market for you, and you know that you have at least the required amount of emblems, you can create a new game with a new Chao Garden saved file.