OP's point is that this isn't valid because neither of the answers are correct. If you're really trying to measure a spectrum then the answers should allow for fuzziness. That is, you have a range/confidence interval of where green ends and where blue starts and in between is neither/both.

But that is wrong. This doesn't test colour perception or vision, it tests verbal classification of colour perception into a forced binary. Everyone could be perceiving the colour qualia 100% identically, but simply choosing different linguistic cutpoints, meaning you can't say this is about vision / perception at all (it may just be about language use).