Now in this discussion, it is important to remember, that the idea of black, in comparison to white had to be perceived as wrong, ugly and sub-human, as an actual enforcement to keep the slaves down mentally. But this mandate was also manifested to provide plenty of cognitive dissonance for those involved, so no accountability to the evil that was done (including the idea of slavery itself) was deemed morally wrong. When a mixed-race child was born having a lighter skin tone, sometimes that child was afforded a more lenient captivity because they were closer to the idea of 'right'. Most of the time their fate was exactly the same as every other slave and their split heritage meant absolutely nothing. But in some cases, their treatment was something closer to that of a servant, than a slave. They could be given the lighter house duties as opposed to working the land. In some, super rare cases, an even more privileged position was given where they might be part of the family structure.
Circa 2016, when you hear of light skin being preferred and dark skin being labelled as ugly, you have to see the origin and the parallels of the past maintaining its presence today. This type of nonsense is still happening in various countries and industries around the world and it is partly enforced by the last people on the planet who should be taking it up. When dark skin is dissed and light skin is praised in opposition, by default or even directly, what you are favouring, celebrating and enforcing is that history, that code and that slave version of divide and conquer.
Perhaps the problem is deeper, perhaps your:
a) carrying that ye olde programming and don't know you are.
b) carrying that ye olde programming, aware that you are and think that it's right.
Either way, you are hating a part of yourself, that you don't want to be associated with. I don't want to hear "yeah I'm black, but I'm not dark". No, you are stupid and your mind is clouded by darkness and the shame of an association. If you are black or mixed and you have a problem with the 'loudest' versions of the hue, then ultimately you have a problem with an element of you. Your insults are seemingly an attempt to distance yourself from the most obvious sign, that in the end you hail from Africa,
Feast of All Saints detailed the lives of free and enslaved people and was just as much about class as race.