The Wikipedia article also includes instructions on how to see these colors, so "never seen before" is a bit strong.
Technically, the technique they are using may give you a slightly different color than the Wikipedia pictures would lead you to. Depleting one color and then looking at the other color would still technically have the original rod firing at some fraction of its recharge rate rather than zero. But that would be the difference between RGB(252, 0, 0) and RGB(254, 0, 0) and not something like those versus RGB(10, 0, 0). It produces nearly the same color.
I'm actually surprised the article doesn't mention it. That the journalist doesn't know about this is not a huge surprise but I'd kind of expect the researchers to know that there is in fact a way to see at least flashes of these out-of-gamut colors for normal people with no special equipment. It's just a static picture that would easily fit into the article.
Technically, the technique they are using may give you a slightly different color than the Wikipedia pictures would lead you to. Depleting one color and then looking at the other color would still technically have the original rod firing at some fraction of its recharge rate rather than zero. But that would be the difference between RGB(252, 0, 0) and RGB(254, 0, 0) and not something like those versus RGB(10, 0, 0). It produces nearly the same color.
I'm actually surprised the article doesn't mention it. That the journalist doesn't know about this is not a huge surprise but I'd kind of expect the researchers to know that there is in fact a way to see at least flashes of these out-of-gamut colors for normal people with no special equipment. It's just a static picture that would easily fit into the article.