I don't understand why the Celebratory Dye Pack (3rd Birthday Gift reward) has 10 different dye kits to choose from, while the Exuberant (5th Birthday Gift reward) has only a measly 4 dye kits available. At this point I have unlocked all the dyes from those 4 kits, which renders the Exuberant Dye Pack worthless to me (since the dyes are account bound), and since that is far and away the most valuable component of the Birthday Gifts, the entire 5th Birthday is relatively useless.
Many of the dye kits remain unavailable from any dye pack, while some others are available from multiple dye packs. I assume the upcoming 6th Birthday gifts will have a new dye pack that hopefully includes some of the previously-unavailable dye kits. However, that doesn't address the problem with the stinginess of the Exuberant Dye Pack's offerings.