I fired up my dye pot (aka very yucky old crockpot I bought at a thrift store for a few dollars years ago) to overdye some yarn. A friend had to give up spinning and knitting in the last few years due to arthritis. I took home lots of her handspun this fall and recently "adopted" another load of it. We do not have the same color sense. At all.
So I grouped her skeins and did three batches of dyeing. The skeins were all different. They are different weights and different fibers. I just grouped them by color. The orange-yellows and oranges were overdyed with a mix of Cherry and Black. (I did a full blog post about overdyeing last April.) I am extraordinarily unscientific about dyeing. I slosh and glug dye over yarn until I like it.
Yellows and greens went to maroon.
Dusty pinks and lilacs went to deeper purples after being dyed with Violet and Black.
And a a straggling vivid yellow skein and an undyed skein (both commercial yarns) went into a pot along with a blue skein. I just used some Cyan and Black.
I think these three skeins really show you what overdyeing can do. All three went into the same dye.
Now I need to decide how to use all these many small skeins in different weights, fibers and colors. I'm considering weaving with them but, you know me, I'll probably change my mind.