I don't speak in terms of black or white magic but I can roughly categorise things according to the intention. If black magic is about harming others... then are we considering "helpful" magic but incorrectly applied being white or black? When a knife cuts a person that is generally bad, but what if its a surgeon cutting a burst appendix?
I would rather say i like to categorise magic according to what actually happens in their applications. Is it saving lives? Is it forcing people to do what you want for personal gain? ..etc. Are we playing judges? Can we trust ourselves not to be clouded by our ego...etc.
But yes I generally get the idea that doing obvious harmful magic and how can it at least drag you down, because many spells have an emotional components.