The curse upon the Amlicites was not the curse of dark skin. Therefore, we are to understand that the curse is more a spiritual curse than a curse of skin color. The Amlicites had brought this upon themselves by willingly rejecting the Lord and his good mercy so that they could have a red mark in their foreheads and a wicked king.
So it is with the wicked. They are forced to admit to their everlasting shame that all his judgments are just (Alma 12:15). They will know this of themselves because in the resurrection they will have a bright recollection of all [their] guilt (Alma 11:43). It is then that they will fully understand that every man that is cursed [brings] upon himself his own condemnation.
Neal A. Maxwell
"On Judgment Day, not only will every knee bow and every tongue confess that Jesus is the Christ but also, as elaborating Book of Mormon prophets tell us, everyone, including those who have lived without God in the world, will also openly acknowledge that God is God and will confess before God that His judgments are just and merciful (see Mosiah 16:1; 27:31; Alma 12:15). Part of the basis for demonstrating the perfection of God's justice and mercy will thus be the cumulative record which we ourselves will have made (see Alma 41:7). Out of this we can be justly judged." (Lord, Increase Our Faith, p. 75)