Purple has no spectral wavelength, it's what your brain sees when seeing a mix of both blue and red wavelengths. It's all in your imagination.
On the electromagnetic spectrum visible light occurs between infrared and ultraviolet. Purple is not violet, there is no wavelength for Purple. The same goes for all the colours on the red side of violet, Magenta, Fuchsia and most of the other girly colours.
All the colours in the Purple region are an optical illusion invented by your brain aproximating what it is seeing. See, Prince didn't have a clue what he was talking about when he wrote that rain song.
Some creatures, like insects and hobbits, can see into the ultraviolet and infra red spectrum, they see colours we can't. What that means is, radio waves, microwaves, x-rays, gamma waves etc, are a colour, just not one we can see.
With that in mind, my new favourite colour is called ABC and is at 64.24 MHz.