Stew colour

[foodiefoodie101]

Is it possible for the colour of stew (which should be red in colour because is a blend of bell peppers, tomatoes & onions) be changed to blackish colour by fresh salmon fish cooked in stew?

My mum just called me to ask how come her stew turned blackish after adding fresh salmon

I know purple cabbage changes the colour of stir fry's etc

But meat and fish shouldn't change the colour of the food it's cooked in right?

Is that all the fish she used? That's a massive amount!

No idea about it turning color

No she didn't cook all of the fish in the picture

Did she fry any of the ingredients before adding? If one or more burnt then I guess that would change the colour.