lol... Porky is going to opinionate. lol
I wonder where the preference for the "paler" or the fair by Europeans came from. I read someplace that the Romans would buy blonde hair from Northern Europeans to make wigs. The North Africans (Egyptians) used henna and other herbs to lighten their hair. But it was taken to an extreme by Western Europeans around the time of the first colonisations which was when they started powdering their faces and bodies and wearing snowy white wigs, maybe they went through some sort of culture shock when they encountered other humans in other parts of the world who were browner.
I read somewhere that the powdered look originated with 'royalty'. It was a 'sign' of 'royal breeding' that you never had a tan. Having a tan meant that you worked in the fields (peasant). So, no royalty wanted to be confused with peasants so they powdered their faces to obliviate any trace of a tan. Over time, court courtiers and other social climbers looking to 'better' their social standing also powdered their faces - to separate themselves from the working classes, i.e people the social climbers did not want to be confused/associated with.
Nowadays, since the industrial revolution, working people have moved indoors to the factories so 'royalty/priviledged' people now have the leisure to sit around and snooze in the sun - which gives them tans that say, "See. I am wealthy - I have a lot of spare time to sit around in the sun' while the 'poor workers' (peasants) stay indoors and do all the work."
Now tans are in... at least until skin cancer kills everyone off. It's all a false, social climbing, class system.
You want my real opinion of royalty? They are a bunch of greedy people who take what does not belong to them and what they did not earn and they also have a very SKEERY inbreeding program which has resulted in a lot of genetic defects. Anyone who wants to be royalty is is probably a prime candidate. lol After all, only a stupid person would want bad genes on purpose.
I think that "black Dutch" referred to the Moors that settled in the Netherlands and their descendants; and with the Irish, I think that "black Irish" referred to the Celtic "type" that are fair skinned, but have very dark colored hair and usually blue eyes. Not all Celtic (gaelic language speaking) people are blonde or red-haired.
I don't know anything about the Moors and the Dutch but what you say about the 'Black Irish' is correct. Black hair, blue eyes, fair skinned, but given sunlight (Ireland is foggy) Black Irish tan up. It's just a variation on type. Black Irish, in my family at least, refers to a person having blue-black hair.