Is there an especial colour for the animals one offers as Korbanot?

Besides the Red Heifer that had to be red, there were no specific conditions as to what colour the sacrifices had to be. Although, the two goats that were brought on Yom Kippur had to be identical in look and colour, there were no conditions as to what colour they had to be. There may be an interesting symbolic message in the above. Since Korbonos represent the person that brings them, the colour of the person or his animal standing for him, is of no consequence.