LaughingLark, I love the colours.
When I woke up this morning, I thought about dandelions.
And I had an idea that I should have BEFORE I threw in the yarn with the acid. Why not test it without yarn first?
I almost ran outside, grabbed a hand full of dandelion leaves, cooked them in water (lalala, microwave) for a few minutes and put them in three different glass dishes. Pure, acidic, alkaline - I did not use any urine for this, sorry.
I also skipped the alum. This was just to illustrate the colour changes.
The pure dandelion "tea" is yellow-greenish. Adding an acid turns it into an almost colourless, only SLIGHTLY red thing. And YES, I said "EUREKA!" after I had put the first alkaline powder into the third dish.
So my thoughts a few days ago where right, after all. I GUESS you could get a soft pink with the acid, BUT it would take tons of dandelion. Using the alkali works better, BUT it can harden and/or affect your yarn, so it should be best to be careful and follow directions for alkaline dye baths based on a book or something, or just use it as a modifier...
I tested the ph value of my dye bath using litmus paper- it's STILL acidic! And I'm not going to add half a ton of sodium hydroxide to turn it around. So I'll probably get the yarn out of it and give it a dip in an alkaline solution...
AFK - need to play with the yarn.
Hope it works. And if it doesn't, I still have a lot of other plants that are waiting for the dye bath.