The Rambam in Hilchot Biat Hamikdash, Perek 8, Halachah 15, writes that a Kushite is unfit to serve in the Mikdash. To quote
...שמונה בעור הבשר ואלו הן. הכושי
There are eight involving the skin. They are:
a) a Kushite;
b) an albino whose skin is white like cheese;
c) one who is red-skinned like scarlet;
d) one who has pure blotches on his skin,17 i.e., [the appearance of] the skin changed because of an internal factor, like a bohak;18
e) [the appearance of] the skin changed because of an external factor, like the scarring of a burn; this is also one of the distinguishing marks that are pure [with regard to tzara'at];19
f) one who has a facial mole that has hair, even if it is not the size of an isar,20 but rather of the smallest size;21
g) one who has a facial mole the size of an isar or more;22h) one afflicted with warts, [when] a person's flesh or skin should distend or the fluids in the skin should distend to any part throughout the body, this is a blemish.
What are the ramifications of this law? What kind of modern people would theoretically be unfit to serve in the Mikdash?