The phenomenon of first strike has always fascinated me. For me the first color to strike the fiber "takes" even if you put other colors over it (not soaking). I "use" this phenomenon when I make my free style fabric with thickened dye and a credit card. Here is an example.
All of these colors were applied then had another color scrapped over it with a credit card but look at how "intact" each color is. First Strike!
Judith wanted some of my embroidery threads to give to her daughter for her birthday. I wound up 30 skeins and put them downstairs. Then I thought, "Hum, I wonder what would happen if..." and so started the experiment.
Nineteen skeins of mercerized cotton embroidery thread (like Aunt Lydia's crochet yarn size 10)
Wetted with just enough water to make them damp.
Below with soda ash added
Washed out by hand
In four lingerie bags for machine washing with color catchers and hot water
Out of the bags
As an experiment, it was pretty good. Each section stayed pretty much the starting color except the yellow which never stands a chance when red and blue are around! Dried. They went home with Judith