Instructions
Buy two differently colored eggs from the Black Market and bring them to the Chao Garden.
Raise the chao in the garden after they hatch by feeding them fruit and petting them.
Continue raising the chao until they are ready to mate. The game indicates their readiness when the chao sit down and flowers begin growing around them.
Bring the two chao together and let the mating process happen as they approach one another and rub noses. Suddenly, an egg appears and hatches, creating a baby chao; this chao may not be born a two-tone chao.
Experiment with the baby chao as you raise the creature if it's born with two tones. For example, use different characters in the game to pet and feed the animal. If it has a certain alignment, such as a Hero or Dark alignment, try feeding it the opposite fruit (Hero or Dark Fruit) to help change its alignment. The change in alignment may result in the chao transforming into a two-tone chao.
Continue breeding and raising different colored chao until you finally get a two-tone chao.