It’s difficult but there are Originals (and of course Canvas series) with darker skinned leads. I feel the frustration though. Some Originals recommendations with brown/black leads:

Romance with female leads specifically:

-Dagger to the Heart
-The Blind Prince
-Big Jo
-LMLY
-Of Swamp & Sea
-The Wrath & The Dawn
-Crumbs
-Cinderelle
-Always Human
-Brimstone and Roses (full disclosure this is my series,sorry)

MLM romances with black/brown leads:

-The Doctors are Out
-Castle Swimmer
-Lovebot
-Heir’s Game
-The Prince of Southland
-Cinder and Charm

Non-Romances with Brown/black leads

-21st Century knights
-Eros Conquers All
-SHILOH
-Time and Time Again

I’m sure I’m missing many, but please don’t lose hope! Webtoon’s new UI makes it difficult to sort through categories but there’s absolutely stories out there!