Alma 3

As the Amlicites set of mark of red upon their foreheads, Mormon makes it clear -

"Thus the word of God is fulfilled, for these are the words which he said to Nephi: Behold, the Lamanites have I cursed, and I will set a mark on them that they and their seed may be separated from thee and thy seed, from this time henceforth and forever, except they repent of their wickedness and turn to me that I may have mercy upon them.
15 And again: I will set a mark upon him that mingleth his seed with thy brethren, that they may be cursed also.
16 And again: I will set a mark upon him that fighteth against thee and thy seed.
17 And again, I say he that departeth from thee shall no more be called thy seed; and I will bless thee, and whomsoever shall be called thy seed, henceforth and forever; and these were the promises of the Lord unto Nephi and to his seed.
18 Now the Amlicites knew not that they were fulfilling the words of God when they began to mark themselves in their foreheads; nevertheless they had come out in open rebellion against God; therefore it was expedient that the curse should fall upon them.
19 Now I would that ye should see that they brought upon themselves the curse; and even so doth every man that is cursed bring upon himself his own condemnation."  (Alma 3:14–19)

Obviously, there was a difference between the mark and the curse.  The curse being cut off from the presence of God or in words, not having the Holy Ghost be with them.  The mark being one of "darkness".  We see this today where some mark themselves.