It appears to be a part of what's (wrongly) known as the Sapir-Whorf hypothesis, which states (as Wittgenstein put it): "The limits of my language are the limits of my world."
I find it extremely hard to believe since, as the quoted portion makes clear, other people presumably have exactly the same biological equipment as anybody else (who isn't colour-blind, for example) and so there's no inherent bar to seeing what somebody else sees. Given that the Himba have no word for blue but many more words for green than we do, I would guess that what we regard as blue they label as a species of green. There's no reason why this shouldn't be the case: words are only labels and there's nothing intrinsically blue about the word blue. Or any other colour.