You see none of these colors are shiny like polished metal.

But I could show you some birds whose plumage glitters with all the hues of the rainbow.

That glittering is called 'iridescence.' It does not depend upon any pigment in the substance of the feathers, but upon the way the light strikes them.

It is the same with the beautiful tints we see on a soap-bubble.

The film of water itself is colorless, but it becomes iridescent.