Normal (left) vs Shiny (right). Credit reddit user skinnysnorlaz They won't appear as a different colour in the field, so you have to attempt to catch them first. They of course can also appear in ...
Meanwhile, Mega Raids see the return of Mega Absol, Mega Houndoom ... is the best way to catch Pokémon. If you get a Shiny, though, it is a guaranteed catch so be sure to use a Pinap Berry.