Expanding on the “West Indian” post
I see similarities between the West Indies and Australia because of their assimilation approach. In Australia, between the 1860s and 1960s, Aboriginal children with fair skin were removed from their families in the hopes of “breeding out” the blackness and were “assimilated” into white culture through domestic work, etc. (also known as the Stolen Generation). Whereas, in the US, in the same period, hypo-descent (or, one-drop rule) was the preferred method of racial categorization.
The West Indies approach, to me, reads more like the assimilation process rather than the hypo-descent process. This suggests that racial categorization is a much deeper, institutional concept based on colonial practices, rather than geography.
Note:I wrote this comment in response to a question about the West Indian post but will post it here as well in order to clarify that post.