I could tell pretty early on as a kid that the boys with freckles seemed to get better favor with the teachers.

I'm going to play devil's advocate and say perhaps you imagined there was an association between having freckles and increase favor of the teachers. How could you know the teacher's preferences without them confiding in you that they prefered freckles? My point is if you are not careful and lack proof, it is prejudice on your own part to think so poorly of the teachers as to believe they are swayed by the freckles.

Also

Luck is definitely a skin color.

I don't think I'd go that far. I feel it's a no brainer to say that minorities are often tasked with more work to get somewhere than someone who fits in with the majority. However, I feel it is off putting to freckleds (or any favoriable skin type) to say they were just lucky. Why? Well if you don't know their individual hardships you don't know how hard they worked to achieve success. Perhaps freckled boy has an abusive but rich father you are unaware of or some other unknown hardship. The point is telling the freckled boys they were lucky because they were freckled is in a way prejudice itself, and only alienates them if they are proud of their accomplishments. That is unless your goal is to be like some others who wish to drive a wedge between the different races.