(yet) Another day of dyeing experiments

Abi and Isaac and I dyed some alpaca sock yarn this morning. (Berroco Ultra Fine, washable). 
In the top photo, the purple (both kids) and the green (mostly Isaac) are ready to be microwaved.  In the second photo, the purple (mostly Abi) has just come out.  She had added the concentrated dye mixture to the yarn before I had added extra water.  The results are quite lovely though:

Purples and blues are so hard to photograph! This picture really does not do the yarn colours justice.

The bi-coloured yarn didn't come out as good in the green department. Especially when held against the bright purple. It was a muddy brown-green, with a lot of poorly-dyed areas.
So I mixed up some more green-blue and overdyed it.  Except, I neglected to add vinegar at first. I think I assumed there was enough absorbed by the yarn at this point. I was wrong.  The colour did not take.  Some of the dye bath had been transferred to the other half of the dish by wicking.  I added vinegar to the green side, microwaved for 2 more minutes, and voila - the water was clear! On the purple side, where no vinegar had been added, it was still bright green. (I'm pretty sure that purple wasn't planning to absorb any more colour anyhow!)  Thus I had an unintentional experiment with vinegar and dyeing.