I've recently come into some fleece and thought I would look into dying it to see how easy it was: very easy!
First was the wool with hot soapy water and dry it.
Then leave it to soak in hot water and vinegar for an hour. Apparently this helps to bleach the wool so that it takes the dye.
While it's soaking, make up some kilner jars of dye. I used Wilton food colouring: about a teaspoon handle, a splash of vinegar and a mug of hot water for each.
I left them on the window sill for 24 hours and then dried the wool with kitchen towel.
I like the mottled texture but if you wanted a more even colour you could probably get that by carding it first.
I've started to make them into wool beads, jewellery to follow soon!
You rip what you sew!