Call it black magic. Who cares?
I think "magic has no color" is one of the many unhelpful SoM mantras that get repeated over and over again (same with "spells you make up yourself are stronger" which i think is totally wrong advice for beginners). Sounds like you've been given this "advice" or "correction," and i think generally it doesn't serve. Maybe it does for you or others, who knows? Any way...
It is human nature to categorize, like it or not. If you don't want to use colors, then describe your magic by its function: love spells, spells of dominion and control, curses, prosperity spells, employment spells, success spells, money spells, etc. Best of luck!