Or not. That’s a common misconception.
The Umayyad Caliphate ruled Spain for quite a while, along with other Arab/Amazhigi folk.
My people can be traced back to Sevilla on one side and Úbeda on the other. Both are in Andalusia (Al-Andalus).
Needless to say, like all Mexicanos, I have relatives that fair skinned with red hair and blue eyes and relatives with mucho melanin, black hair and dark eyes.
Just depends on which genotype and phenotype they acquired in the wonderful mestizo pool.
Dark characteristics are dominant. Doesn’t necessarily mean you are more Inca, Azteca, Maya. It could be your Arab, Amazhigi genes letting their freak flag fly.
Now, as far as what is valued among our mestizo culture, that’s a different conversation. And you are spot on. And as you said it’s slowly dwindling. A lot of that is based on historic and ethnic ignorance. Sprinkle in some self-loathing in there too.
An intriguing phenomenon are my brethren in northern New Mexico. Most identify as Spanish and not Mexican. However, ask them for a tortilla and they will not give you an egg/potato quiche.
Nomenclature can be confusing. What you are genetically and how you identify culturally, ethnically may not be the same.
I will use myself as an instrument. I’m American (nationality), Mexican (culturally), Mestizo (ethnically) and Tejano (by the grace of God, subculture).
As humans we are are all mixed, some more than others. It’s math. Humans have been traveling and having sex with each other for thousands of years.