LONDON — As a 17-year-old working at a Benefit makeup counter here, Florence Adepoju was often disappointed when the company released a new product that didn’t suit her dark skin.

“Everyone on the counter would get one, and I’d be like, ‘That’s not the right shade for me,’” she said. She also wanted luxe lipsticks in the sort of unusual colors she could find only in drugstores.

So Ms. Adepoju spent four years earning an applied chemistry degree in cosmetics and set out to make the colors she coveted, in flashy packaging inspired by her love of hip-hop, both its sound and its aesthetics.

Two years ago, she introduced MDMflow, handmade rose-scented lipsticks in shades like juicy orange, emerald green and brilliant blue, sold in gold-colored aluminum bullet casings. (She wanted packaging that wouldn’t look out of place, she said, in the Nicki Minaj/Drake video “Moment 4 Life,” in which Ms. Minaj is seated at a blinged-out dressing table.)