Every color has shades within its colorway. < p> Even a single pigment color DOES have different qualities/shades within in it. Re watercolor...the shade depends on how much or how little water is added to the color, as well as if you use a dry ( none wet paper) or wet ( a dampened paper ) on which to paint.
By adding more water and/or painting "wet", you are able to paint a violet hue, by using a purple ( and there are many different shades, as well as mixes in the purple range ) color and a LOT of water.
It’s just a lighter shade of purple. In modern color theory, which is used in computer screens and printers, there are 6 main colors. Red, green, blue—and their opposites cyan, magenta, and yellow. Everything else is a combination of those. And if you combine them with white or black, you can control how light or dark they are.