Assertion: black swan's feather | /r/CapableOf | obtain their colouring
Facets:
value: through coloured pigments in the keratin
type: MANNER
Source sentences:
text: Feathers obtain their colouring through coloured pigments in the Keratin of which the feathers are made and through carotenoids (any of a class of yellow to orange pigments) and Porphyrins pigments (which provide red, green and brown colouring).