Why would you need to ask that cantankerous corpse? I am equally as qualified as he is for such questions!
The most notable “ghost of colour” (as you put it) would be our dear Cleo. As she lived in Egypt, her features as the typical dark air and eyes that are found in the country. Also from Egypt hails the hard of hearing Mummy that resides in the graveyard.
Constance’s husband the Marquis de Doom was from china. Though he keeps himself hidden out of shame, like the rest of her husbands do, he is still somewhere among the furniture.
A few other foreign ghosts such as Irv, I.L Beback, Hap A. Ritton, Franz Geiger and Wathel R. Bender also come from exotic parts of the globe.