Here is a related example, from Mormon 9:
4 Behold, I say unto you that ye would be more miserable to dwell with a holy and just God, under a consciousness of your filthiness before him, than ye would to dwell with the damned souls in hell.
5 For behold, when ye shall be brought to see your nakedness before God, and also the glory of God, and the holiness of Jesus Christ, it will kindle a flame of unquenchable fire upon you.
Reading these verses, the word "nakedness" stands out. At the time of the Fall, Adam and Eve realized their nakedness and God clothed them with coats of skins (see Genesis 3:21).
Suppose rejecting the covenant entails taking off the coat of skins given by God and breaking His commandments. (In a sunny climate, this could certainly impact skin tones, but I consider that to be of secondary importance relative to the rejection of the covenant.)
Nakedness also happens to be a commonly used descriptor of the Lamanites who have abandoned the covenant. A good example of this is found in Alma 3:
So in Mormon 9, Moroni is overtly telling those who do not believe in Christ that they see their nakedness before God and also behold His glory. "Nakedness" in contrast to the "glory of God" makes a lot of sense in the context of the Hebrew root 'addereth' meaning "garment, glory, goodly, mantle, robe". It's a Hebrew pun, perhaps?
5 Now the heads of the Lamanites were shorn; and they were naked, save it were skin which was girded about their loins, and also their armor, which was girded about them, and their bows, and their arrows, and their stones, and their slings, and so forth.
6 And the skins of the Lamanites were dark, according to the mark which was set upon their fathers, which was a curse upon them because of their transgression and their rebellion against their brethren, who consisted of Nephi, Jacob, and Joseph, and Sam, who were just and holy men.
The case for all of this symbolizing covenant-keeping gets stronger the more we look into it, in my opinion.
In future posts on this subject, I'll demonstrate numerous examples in the Book of Mormon where the terms "curse" and "darkness" are associated with sin and rebellion. It is helpful for me to think of this as a symbolic rejection of the covenant. (I don't find it very helpful to think of it strictly as skin tone, which is perhaps where our modern sensibilities might jump if we take it out of context.)