Some tables have white dice, and others have black -- is there any distinction between which color is used through the book?

I like how it distinguishes between the main table and sub-tables for "People You Meet on the Road", but otherwise I haven't been able to figure out a theme for which is which -- is it mainly just that Part 1 is uses white (except in PTMotR), and part 2 uses black (except for the City Rule/Themes tables)?

Yeah, it's roughly that the black ones are the main tables and the white ones are secondary tables for adding more detail etc, like having two levels of bullet points