So-so glad you went there! I was actually hoping that you eventually would. First, the author details the man's "complexion" which is defined as being a person's "natural skin tone." Your author is only elaborating on that natural skin tone when he references the sun and weather in detailing the depth of his "natural discoloring" which is why he says, "as if" instead of "was".
Second, and once again, "you're assuming" that the author was referring to white women! The fact that he was envied by men could just as easily be in reference to those slaves who envied this free man of color. "Dark and swarthy natural skin tone, jet black eyes, hair of the same color."
"Complexion" as it is defined in just about every dictionary means, "natural skin tone." Look it up yourself or simply stick to your own definition. Your choice.
But I am curious as to why you remain so steadfast that TJB had to be a white man when the only man of record with that exact name and description during the period was a free man of color? Is it because it has to remain a white thing? I mean, if you stop and think about it, all the more reason for the author to have remained anonymous. So your post above, on all points, simply expresses extreme bias without any evidence whatsoever, and actually quite to the contrary, for maintaining that extreme bias. Very, very curious, indeed.