“Inside a color band are many different shades and violet IS a shade of PURPLE!”
Violet has its own part of the visible spectrum. Purple is a not part of that spectrum. It also has to have frequencies of red mixed in.
Can we just be happy that Purple exists as the lovely mystery (or not) that it is?
But DO allow ME to have mine.
And the picture of the color spectrum, used in the article, is PURPLE! Violet is a different shade. And this isn't a case of "a color by a different name" is that color.