Yes, you can get the shiny versions of Froakie, Frogadier, and Greninja in Pokemon GO, after they were added to the game on August 12, 2023, as part of the Froakie Community Day.
Any Froakie you encounter has a low chance of being shiny, while you can get shiny Frogadier and shiny Greninja by evolving a shiny Froakie.
You can tell if the Froakie you encounter is the shiny version by its lighter color. Shiny Froakie is a very pale blue compared to its standard version.
Froakie Shiny Odds
The odds of Froakie being shiny in Pokemon GO are 1 in 500, or 0.2%. This is the standard shiny odds in Pokemon GO.
Unfortunately, there’s no way of increasing Froakie’s shiny rate, and it even remains the same on the August 2023 Froakie Community Day.

How to Get Shiny Frogadier in Pokemon GO
To get the shiny version of Frogadier in Pokemon GO, you must evolve a shiny Froakie. This is because shiny Frogadier does not spawn in the wild.
To evolve a shiny Froakie into a shiny Frogadier, you need 25 Froakie Candy.
The shiny version of Frogadier has a light blue body, a dark blue face, hands, and toes, and a white scarf and fingers.

How to Get Shiny Greninja in Pokemon GO
The only way to get the shiny version of Greninja in Pokemon GO is by evolving a shiny Frogadier.
To evolve a shiny Frogadier, you first need to get a shiny Frogadier by evolving a shiny Froakie using 25 Froakie Candy. Then, you can evolve your shiny Frogadier into a shiny Greninja using 100 Froakie Candy.
Greninja has one of the coolest shinies in the whole Pokemon series. It is black with a red tongue and has white circles on its body.
