What we call "magenta" is the sensation of both red and blue color-sensitive cells in the eye being excited at the same time. There's no single wavelength that produces this effect (unlike e.g. yellow). The closes you can get is violet, which looks faint to the eye.

A rainbow gives you both red and blue; mute everything else, and you'll get magenta. That's what magenta pigments do when illuminated by white light (which is a rainbow scrambled).

It never clicked before that yellow and magenta are snowflakes to each other in this regard. I thought they were equals, but magenta is more majestic!

Saying a wavelength doesn’t do it doesn’t make any sense. If you can perceive it visually, a wavelength is doing it.