"Many times did the Lamanites (people of color) attempt to encircle them about by night, but in these attempts they did lose many prisoners. And many times did they attempt to administer of their wine to the Nephites (Mormons), that they might destroy them with poison or with drunkenness."
-- Alma 55:29-30 (Book of Mormon)
Look at what this verse in implying in regards to the fictional race war between the Lamanites and the Nephites. It's saying that the people of color will attempt to escape from being oppressed and enslaved. To prevent that, you just kill them. It also makes the false racial stereotype that all people of color are drunks.