A large part of colour is association. At least for me, as a visual person, it is.
When I see a specific kind of blue my braincells run to the "blue library" and come back with things like: "Oh, this is the kind of tired, jeansy blue your primary school work books used to have". "You' shouldn't really like it". Or: "Wow, new kinda blue here! Let's file it under "fascinating-plant-from-the-botanical-garden-blue".
So, today it's purple. Beautiful, still, but not a friend. Though it carries many associations for me it stays secretive, quiet, and when she speaks up, it's not always what I want to hear.
She gives my world of colour some edginess. And that, in the end, makes the whole just perfect.