etymology of "pelos chinos"

What is the etymology of the Latin American Spanish expression “pelos chinos” which connotes “curly hair” in English?

This site, in Spanish, claims in this sense it originates from the use of the Quechua word “china” (girl, woman) to refer to domestic servants. Once African slaves were imported they mixed with indigenous people, and their offspring became known as “chinos.” So eventually “pelo chino” came to refer to the kinky hair of mixed-race people.

I cannot vouch for the accuracy of this information. I am just reporting what the site says.