Result

setting up

soaking the yarn

drying over the bath

I was a bit iffy about how this was going to turn out. I put the yarn in the dye and while the silk went violet immediately, the camel just said yeah, so? (see pic with red spatula) - I was prodding it forlornly at this point as if poking the stuff with a bit of plastic ould make it more permeable somehow. 'Ah nuts' I thought. 'Pod was right and I've ruined hours of work'. But I kept ploughing on, heating gently, simmering for twenty minutes then leaving it cool. Meanwhile, to stop me prinking, I cleaned the oven, washed down the cabinets and sorted out the hall - the things I will do to stop myself from fussing over a project. Yes, for me, housework is a displacement activity.
Ah well, it turned out fine in the end. There is a funkier stripe to it than I thought it would be. The silk is a deep bluebell colour while the camel has turned a dark pansy purple. I think it will work up well, if a little busier than I pictured. The wool that I used to tie the skien has gone a most delicious shade of violet - I think I will have a go with some falkland I have lurking in the stash.
Just as an aside, it smelt terrible while the stuff was simmering. I don't know if that was the yarn, the vinegar or the dye or what but I hope it doesn't stick around on the yarn or else my shrug is not going to be a popular wear.