It looks like the mystery minis are slowly making their way into stores. These are essentially Funko's answer to blindbag ponies if you don't remember their announcement a while back. According to the folks over at MLP Arena, a good amount of these have "variants", some with the black color, while others use the traditional design their larger counterparts run with. Have a list from VioletCLM:
3 Derpy
3 Pinkie
3 Vinyl Scratch
3 Rainbow Dash
3 Doctor Whooves
2 Octavia
2 Bonbon
2 Spitfire
2 Lyra
1 Fluttershy
24 Total
Now on to the bad news! According to Texasuberallies (who also sent all these pictures over), It looks like, unlike blindbags, these don't have any kind of identification that allows you to pick specific ponies or colors.