Before they add in colored chocobos they have to figure out what their purpose is. Getting out the rental and personal chocobos, you should be happy about. Just a few weeks ago it was said that the personal chocobos might not make it in 1.19. Now they are! Maybe they had to edit down some plans (such as colored chocobos) in order to make this happen sooner.

Again, if you're going to add colored ones. You have to figure out what different abilities they will have while not being broken. (red crossing steep hills, blue running over lakes, ect)

I think having different colors for the sake of having them is not good enough. Might as well wait and figure something more clever out that has to do with their coloring.