Actually white eyes are when they are submissive, there is no freedom in that moment or ability to resist what they are told, so no color. Exp. when Avina does dominate him, his eyes with go white, as will Violet's. Black is when they are strongest, they have no emotion and are calm which makes them stronger. Of course seeing that this is new breed it can be reversed.
Hmm that's true so maybe they can feed as human form but they aren't able to get as much as they need?
A vampires instinct revolves around freedom and greed versus control. Most of the time, freedom and greed being the stronger of the three. Vampires hunt and feed alone, because they are greedy when it comes to their food, or blood. Often the times which a vampire will kill another, it is caused by blood, and the lack of control that comes with the taste of it. The only two exceptions being in the case of a changeling, and a very well controlled older vampire. Changelings are just like newborns in the case they are often unable to lore their victim into the sense of calm needed to drink from them, and the Elder has to do it. Once they are strong enough they earn the freedom to hunt for themselves. The elder that changes them is often the one that makes them submit, and they have a mental connection with their changeling for the whole time they are alive. Until that vampire makes another, he or she lives with the elder. If one vampire kills another, by the laws they have to fight the first elder of that vampire for the right to live, unless the rare exception of taking their place is given.
That turned out longer than I thought it was going to xD But I think that's is the basics of it.
Edit: Awesome going to read!