Outside of pruning and planting, I've made a few pairs of plain socks and sorted through my stash--lace yarn in this basket, sock yarn in that basket, and the "What chemical was I imbibing when I purchased this stuff?" yarn in a large plastic bag over there.
Some of the WCWIIWIPTS yarn was actually very nice, but the colors were either insipid or frightful.
..rustle...clank....out came the cauldron and Potions kit....
Here is a Before photo of Schaefer Andrea in the Louisa May Alcott colorway. I. Hate. Brown.

A flick of Chinese Fireball Red dragon scales...

I didn't much care for the green in the Andrea Helen Hayes colorway either.

A bit of Gillyweed and some Merpeople hair later...

Consultation with my Advanced Potions textbook allowed me to transform Fleece Artist's pale blue and yellow Cornflower colorway into something a bit more interesting:

And Fleece Artist's lackluster Saffron colorway was transformed into a spicier flavor:

I used potions with hues similar to the colors in the underlying yarn so I wouldn't end up with muddy colors. The process works surprisingly well, although I am still adding red to a particularly stubborn skein of ghastly beige Malabrigo laceweight in an effort to make it attractive. (It was billed as Peach, but the color I received bore no resemblance to either the on-line picture or the namesake).
One word of advice if you decide to try this at home. Do NOT add Eye of Newt to your potion mixture. Otherwise, you'll end up transforming your skein from a plain, but mainstream yarn:

Into something like this:*

A little vitreous humor (snicker).
*Actually, this incredible skein of handspun was created by the fabulously talented Jacey Boggs. You can find this yarn, as well as other amazing creations, at her web site: Insubordiknit.