purge unused pens?

[Anonymous]

I haven't used the attribute manager that much, but one thing I found very useful was the ability to purge unused materials. I can't seem to do the same for pens. Is there something I've completely over looked? The 'purge unused' button is greyed out when editing the pens attributes.
All these rainbow coloured pens have no use to me and It just makes it a little messier if I want to edit pens or change the pens of an element. Anyone have any answers to why you can't delete pens, you can only edit existing ones? I know it must be possible, but it doesn't seem obvious.

[Anonymous]

Hello Neil,

You can't purge pens as materials, lines, fills, or layers…
You will have always ALL the 256 colors.
But you can change each color pen as you want, by example turn the "non need" pens to white, will reduce the rainbow effect…