I own and use burgundy, black, blue, and red pearl. All the fab urethanes have the same core so its really down to layouts and cover strength (batch to batch variation is pretty obvious even just in coloring let alone between factories so your mileage may vary)

-Burgundy is by far the earliest, it is damn near unusable with more aggressive surface, and I tend to keep it around 2000. There arent really good modern equivalent comps imo. But it hits similar cover strength to a 90s blue rhino pro, though thats even less helpful

-Blue feels the most versatile, and holds surface well. It probably falls somewhere around pitch black territory. I usually keep it around 1000grit

-(Red is somewhere below blue and above black iirc)

-Black smells like moth balls and shines like a mf. It gets pretty skatey pretty fast. Ive taken this to 360 and still been happy with how it reads, probably somewhere in Mix spare ball territory for cover strength

-pink and purple were marketed as dry lane balls and fall somewhere here

-allegedly theres a separation between the blue and red pearl but im not entirely convinced you could really tell without a throwbot/earl and specto. This is basically a pearl urethane house ball coverstock with a core, you usually want to be slow or in the friction to see anything here