There are different costumes of Emeral with different character colors.

Ninja Emeral: Shadow 1, Rouge 2, E-102 3.
Mega Emeral (Megaman): Sonic 1, Chaos 2, Cream 3.
Hallow Emeral (Halloween): Tails 1, Rouge 2, E-102 3.
Santa Emeral (Christmas): Kn. 1, E-102 2, Chaos 3.
My Custom Emeral: Kn. 1, Chaos 2, Sonic 3.