It seems when you read stuff from the 16th century to mid 17th century, the moors are usually depicted as black. For instance, in the play ‘The English Moor’ written in 1640, there’s a scene where a female character dresses as a moor to disguise herself.
She actually stays in his house, in disguise: Quicksands dresses her up as a Moorish servant, with blackface make-up and a veil. When she complains about the "black painting", asking "Would you blot out / Heaven's workmanship?" he counters "Has heaven no part in Aegypt? Pray thee tell me, / Is not an Ethiopes face his workmanship / As well as the fairst Ladies?"
Of course, there’s also Othello who is often referred to as being a black moor.
However, by the time Robinson Crusoe was published in 1719, the moors are no longer described as black. Throughout Robinson Crusoe there’s a distinction made between ‘negroes’ and moors. Daniel Defoe never describes the people he refers to as moors as being black when his character is enslaved in Morocco. It’s only when his character sails to West Africa, he then gives a description of black people. And by the 19th century, the moors are firmly considered North African/Arab Muslims and not black in historical books like Moors in Spain (published in 1886). The historical book only mentions black people once in its account of moors in Spain and that’s only to say the sultan’s black guards were hated.
Popular feeling ran very high, not only against the Sultan, because he would not wear sackcloth and ashes or pretend to be an ascetic, but against his large body-guard of "Mutes," so called because, being negroes and the like, they could not speak Arabic.
So why were moors originally depicted as black in the 16th and 17th century? And why did this change in the 18th century?
Some people are saying that this is because all non-white skin was considered black. This is not true. When people in England said black in the 16th or 17th century, they very much meant black. The numerous travel accounts from the 17th century show this. For instance, Edward terry travelled to India in 1616 and gave a description of the people in India.
Now for the complexion of this people, they are all of them of a sad tawny or olive-colour; their hair black as a raven, very harsh, but not curl’d. They like not a man or woman that is very white or fair, because that (as they say) is the colour of lepers, common amongst them. - Race in early modern England by Jonathan Burton
In the 1640s, a Puritan gives a description of a black prostitute in London. He goes on to say that she wore a blonde wig (faire Hayre), but it would have done her better to try and and change her black skin then she might at least be brown (ware).
In the first Night’s Search in particular, Mill provides misogynistic and racist descriptions of the prostitutes whose presence he allegedly monitors and polices. The forty-eighth section, for instance, is a portrait of ‘a black impudent Slut that wore a dressing of faire hayre on her head’. ‘But couldst thou change thy skin’, he mocks in malicious tones, ‘then thou might’st passe / For current ware, though thou art nasty trash. Most of these depraved women, he is gratified to report, end up incarcerated in Bridewell. - Nightwalking by Matthew Beaumont
So yes, it seems people very much could distinguish between black skin and other skin colours like Brown, which they sometimes referred to as Tawny or olive colour or even ware.
While there's always more to be said, this previous answer by /u/sunagainstgold is a good start.
Judge Ford stared at the table, at Theo Theodorakis’ hand. A calloused hand, a healed cut, the shiny slash of a burn on the deep bronze skin. She lowered her hands to her lap. His Greek skin was darker than her “black” skin.
-Ellen Raskin, 'The Westing Game'
What we think of as classifying people by skin color has, of course, little to do with actual skin color. This was true in the European (and Near Eastern, and West African) Middle Ages; this was true in the early modern era; this is true today.
What has changed, however, is the criteria for dividing people into groups to which to apply an ideology of skin color. Factors like religion, geographic origin/ancestry, and social status--especially enslavement--rise and fall in importance in calculations of "black" and "white."
I've talked before on AH about how black/brown and white in medieval Europe operated in general under the conveniently linked ideas of climate and religion. That is, the further south, the darker the skin color. Medieval Arab writers also repeat this theory, stressing the 'whites' to the north as well as the 'blacks' to the south. (They actually use the term 'blacks' as a noun).
In the medieval Christian European view, unlike the Muslim North African-Near Eastern one, there was Christian Europe in the north, Muslim Africa to the south, and eventually pagan Tartar Asia to the east. The simplification of "Muslims" and "south", along with the trans-cultural tendency to equate darkness with bad things, generally resulted in Muslims/Saracens=>Moors being associated with dark skin.
There is definite weirdness here, though--and a prime example actually comes up in your quotes: Ethiopia. Hildegard of Bingen in the 12th century uses "Ethiopian" as a substitute for "dark skin"; in the 15th century, with Ethiopian Orthodox Christians in residence in Rome and attending Church councils, they're sometimes depicted in art as white-skinned with red hair. And "Europe" and "Ethiopia" are even mixed up (the words) in some copies of popular texts!
But even that example demonstrates how religion and geographic origin of ancestor kind of swam around each other in determining ideological skin color, moving from the medieval period into the early modern era.
Over the course of the 17th century, however, religion changed and decline in importance (but definitely did not vanish), and social status rose in prominence. What happened here can basically be summed up as: slavery.
This wasn't new. In medieval Iberia, maurus/moro was more associated with enslavement than Saracen/sarraceni (also linked to whether Castilians or Aragonese were writing the text) and Turk also less so. But it doesn't seem to have been that big a deal, as your examples show.
It's a complicated process that wraps its tendrils around Native Americans and conversion (or lack thereof) to Christianity as well. But scholars have shown that, in general, ideas of "enslaved" and "black" built up each other in 17th century British North America. Social status--enslavement or free--became the metric for determining what it mean to be black.
The really interesting thing to me--mostly because I learned this literally 36 hours ago (nearly to the minute)--is that this development followed some centuries later on a development that had occurred among medieval Arabic writers and West African elites. Regardless of similarities or differences in skin color, "black" was associated (though not always) with enslaved members of the population.
The answer can be summed up as "It's Complicated," I suppose, with lots of flexibility and fuzziness and steps forward and backward. I also need to read more about the Ottoman Empire and see how changing European perceptions of it might play a role. But this is at least a messy version of filling in your question.
My apologies for the delay in answering.
Not exactly what you're looking for since 16th-17th century western/central european literature is well outside my area of expertise, however I have written an answer that describes the composition of the 8th century force that conquered some territory and laid the groundwork for the development of al-Andalus. You can find that answer here.
In reference to some of what I've written in that post I would like to point out a few things. Firstly, as I've said before - "moors" isn't really the best term for a modern person to use. It's a vague term that christians used to lump all sorts of different people from different places and eras in together. I think if you're talking about Islamic Iberia it's best to just refer to the people there collectively as "Andalusis" if that's who you mean.
It's more specific and identifiable who you're referring to and doesn't have the awkwardness of terms like "moors" and "saracens". It's also a term that can be inclusive of Christians and Jews, many of whom were important figures in the administration and academia of al-Andalus. If you mean a more specific group, then you can refer to them specifically: "Andalusi christians" or "iberian christians", "Andalusi berbers" etc. This all brings me to my next point, one that really is important for a question like what you're asking here.
So, secondly: Who is it exactly that you're asking about? Which people in al-Andalus are you asking about? There's a reason why "moors" isn't really an accepted term. One of those reasons is that it's never really clear who the author is actually talking about, and sometimes it isn't even clear what period they're describing. People like to imagine that those living in Islamic Iberia were all just arab muslims, but that's far from the case. In fact, most weren't, not even most muslims. They were diverse. So when we hear "moor", we have to wonder - who do they mean? And from what era? Time is important because the ethnic composition varies drastically between 8th century Gibraltar and 13th century Valencia.
Are they talking about Andalusi christians descended from Hispano-Romans in Iberia? or perhaps Visigothic Andalusi christians? Are they talking about Visigothic Andalusi Muslims like Ibn al-Qūṭiyya? Are they talking about Mizrahi jewish immigrants from places like Baghdad? Are they talking about local Andalusi Sephardim instead? Or perhaps Arab migrants to al-Andalus? Or even local Arabs? Are they talking about Berbers, descended from the original conquering force in the 8th century? Or perhaps Berber migrants from Ifriqiya? As Ruggles notes, al-Andalus even in the late years of the 15th century was still known for an unusually high level of diversity for the time, something still remarked on by the common usage of the term 'convivencia', a term Ruggles says is used to describe the richness of artistic styles produced by that diversity.
And when you examine descriptions of prominent Andalusis - for example, via Ibn Hazm we have descriptions that show almost all of the Umayyad caliphs as being primarily blonde haired and commonly blue-eyed, as Christian women from the north were commonly the fathers of those caliphs. Abdul Rahman III's mother, for instance, is now generally thought to have been either Frankish or Basque. The point here is that al-Andalus wasn't remotely as uniform ethnically as the later western & central european literary sources might give you the impression of being.
So I can't really answer your specific question, I can just give a bit of detail on the diversity and ethnic makeup of al-Andalus. At this point, I would suggest that, given how the historiography of al-Andalus has developed and changed over time, that perhaps many of these playwrights and authors simply weren't well informed on the cultural and ethnic makeup of al-Andalus. Equally possible is that accuracy just wasn't their concern.