Yes, you can catch a shiny version of Groudon in Pokemon GO. However, the chance of you encountering one is very small.
If you beat Groudon in a Raid, there is a low chance that the Groudon you encounter is the ultra-rare shiny version of this Legendary Pokemon.
The exact chance of finding Legendary Pokemon in Pokemon GO may be low, but it might not be as rare as you think. In fact, you’re more likely to encounter shiny Legendaries than the shiny versions of standard Pokemon!
Another way of getting a shiny Groudon is by receiving it through a trade with another player. Although, to do this, you will need to know how to make special trades in Pokemon GO, in addition to finding someone who is willing to trade one!

What Color is Shiny Groudon in Pokemon GO?
The shiny version of Groudon is a lime green color. This makes it stand out a lot from the bright red standard version of this Legendary Pokemon.
While its body is green instead of red, the rest of shiny Groudon remains unchanged. It still has white spikes, claws, and stomach, as well as yellow eyes, like the normal version.
This shiny variant is almost the complete opposite of the standard version, but it still doesn’t stand out as much as the brightly-colored shiny Kyogre.

Can You Get Shiny Primal Groudon in Pokemon GO?
Yes, you can get a shiny Primal Groudon in Pokemon GO. To do this, you will need to use Primal Reversion on a shiny Groudon.
You will also need to collect a whopping 400 Groudon Primal Energy to spend on your shiny Groudon!
The shiny version of Primal Groudon is a very cool black and gold color scheme, making it one that no shiny hunter will want to miss out on!

Groudon is just one of the dozens of Legendary Pokemon in Pokemon GO. What’s more, most of these Legendary ‘Mon have a shiny version to catch too!