Its one of the few things I still don't get either
To color it you need access to the stables (either by FC or own house)
To get the berries you either buy them of the AH or grow them yourself but you need access to a gardening plot therefor access to an FC or own house

We are talking about painting a bird here? >_>
Why couldn't they add 2-3 flower pots to your inn room? or your personal FC room at least so you can do some gardening your self.

The stable could have been resolved by putting a public stable in Ishgard (where the current stables are now)