their diet

[a] Flamingos are pink because of their diet.

from carotenoid proteins in their diet

The pink color of flamingos comes from carotenoid proteins in their diet.

from carotenoids in crustaceans's diet of animal and plant plankton

The pink or reddish color of flamingos comes from carotenoids in crustaceans's diet of animal and plant plankton.

they eat

Yes, places’s true… flamingos are pink due to the food they eat.

from the shrimp they eat

Flamingos' pink color comes from the shrimp they eat.

from beta carotene which is found in high numbers within the algae, that flamingos eat in their wetland environment larvae, and brine shrimp

The bright pink color of flamingos comes from beta carotene which is found in high numbers within the algae, larvae, and brine shrimp that flamingos eat in their wetland environment.

Astaxanthin

Astaxanthin is the reason flamingos are pink (or at least flamingos in the wild; in the zoo they may be fed artificial dyes like farmed salmon–see my video Artificial Coloring in Fish).

from the algae they eat

Flamingos are numerous in Africa and get their pink color from the algae they eat.