In truth, you may have heard recently 'Magick has no color', but do you know what it really means? It simply means magick is neither good or bad, it depends on you and you only. It depends on your intention. You can have a positive intention or a negative intention, that does not make you 'evil'.
If you use a spell to break up a relationship for example, you do not suddenly turn into this cruel and merciless person. You can do a spell that is considered negative and you can do a spell that is considered positive. Going back to that breaking up a relationship scenario, what if the relationship was abusive? What if you did the girl or boy a favor? That isn't really negative at all. That negative scenario would turn into a positive scenario as you would have stopped an abusive relationship.
What I am saying is that what you call 'White magick' or 'Black magick' is really meaning your positive or negative intention.