Dark Magic is merely magic that requires a sacrifice that isn’t just your own magic; doesn’t even have to be a living thing. You need something to be used in order for dark magic to work. Any type of transfiguration is a type of dark magic, because you use the matter of one thing to change it to another. Rituals are dark magic because of their usage of sacrifices, along with blood magic because you are using your own blood. The most surprising dark spell is the patronus. It isn’t even a charm, it’s a dark ritual. You have to sacrifice happy memories to use the spell. Light magic is magic that doesn’t require anything except intent and your magical energy. Charms are an example of this, and it isn’t dark because even though you need an object to cast a spell; the only thing that is used to create the effect is your own magic. Elemental magic also is light magic, because your element already exists. It is merely being influenced using your magic to do your bidding. Most "dark" curses aren’t even dark at all. The Imperious curse and the Cruciatus curse are not "dark." They only use your own magic to complete the task; pain and mind-control. However, the Avada Kedavra curse is dark magic. The sacrifice needed to take someone’s life is a tear in your own soul. Not many people know this, but only that specific curse causes it to happen. Any other acts such as torture or killing doesn’t do anything to it. Neutral magicks includes magic that requires you to have magic, but it doesn’t use it; such as potions, herbology, runes, etc. Your core is the color of your natural affinity.