You did send a specific wavelength to your retina, but that wasn't violet. Because violet is a construct by your brain.
Color is not a property of wavelength. There's nothing special about photons wiggling in the 380 to 750nm range.
In general it's not necessary to be this pendatic, but given the topic here, I think it's important to realize this. It takes a while because we are so good at projecting our internal experience outward.
In my personal conception, violet is the kind of colour at the lower edge of the rainbow, which is a single wavelength. And purple is what the brain constructs. However, of course, the names of the colours are themselves vague.
Maybe that's a language issue, because purple and violet are color names around here.
And as such, they are both a construct of the brain, as any other colors, like... white.
What we label as "violet wavelength" is only a narrow projection of our experience outward. Case in point, we don't have such colorful (eh) names for other EM wavelength.
I say narrow because you could take this pure laser and change th surrounding and you will inevitably perceive it differently, even though the power and wavelength are the same.
Hmm if you talk to a colorist violet and purple are 2 different colors one more on the red and the other more on the blue. That’s still the construct of 2 wavelength colors. So a made up color of our brain that doesn’t exist.
If I shine some wavelength to your eyeball and you say "it looks blue", but then I change the surrounding and now it looks white, I don't think you would conclude that the original wavelength is blue.
We have a many examples like this, which prescribe that vision is not at all an accurate wavelength measurement device.
Color is not a property of wavelength. There's nothing special about photons wiggling in the 380 to 750nm range.
In general it's not necessary to be this pendatic, but given the topic here, I think it's important to realize this. It takes a while because we are so good at projecting our internal experience outward.
Remember the blue / black dress?