Quote:
It was stated in the June 19 Topics that a chocobo’s appearance would change along with its attributes. Due to an extension of the testing period, these changes will now be implemented in a following version update.
That sounds to me as thought your chocobo won't change shape or size based on the numerous variables that can affect a chocobo--strength, endurance, and so forth--but I wouldn't consider color a changeable attribute. Also, the web site has a nice picture of a Mithra on a black chocobo; my guess is that if they had to pull all the colors out of the update, they would've found a different image to use on the page describing chocobo raising.
My guess is that the five different types of eggs ("somewhat warm," "a little warm") represent the five different colors. Color would be a native and immutable characteristic of the things, not an attribute.
At least, I hope that'll turn out to be true.