This is a concern that many people have. So the question: Is dark skin a curse? Does God really look at the color of our skin? The answer: of course not! In the Book of Mormon the Lamanites were cursed because of their own disobedience. The Lord said early on the the people "Inasmuch as ye shall keep my commandments ye shall prosper...and inasmuch as thy brethren shall rebel against thee they shall be cut off from the presence of the Lord." (1 Nephi 2:20-21) The Lamanites did not choose to follow the commandments of the Lord and they rebelled against the prophet, thus they were cursed. The curse was that they were cut off from the Lord's presence. He no longer was there to help or guide them, until they would repent and return to him. The skin of darkness was placed upon them to distinguish them from the Nephites.
Later on in the Book of Mormon the Lamanites did repent, and they were blessed again with the help of the Lord. The prophet Nephi said of the Lord, "He inviteth them all to come unto him and partake of his goodness; and he denieth none that come unto him, black and white, bond and free, male and female; and he remembereth the heathen; and all are alike unto God, both Jew and Gentile." (2 Nephi 26:33)
I know that the Lord looks at the level of our obedience, not at the color of our skin or any other physical trait or charecteristic.