I really am at a just try it and see, with little control over what may happen.
After I mixed the colors, I tried the yellow green and blue violet on my samples. I set up my samples by sewing them on a light cotton fabric and stretching the fabric over a small cardboard box. I used a brush to dampen the samples and apply the yellow green. I sprinkled on salt. I painted the violet color on the surrounding cotton background fabric.
Of the samples, I like the lower left habotai the best.
I like the lower part of the violet background even better. I painted on a stronger violet than I wanted so I brushed on some water. The dye had already begun to set in some places but spread in others making a swirly effect. The salt magnified the effect further.
Once again, this is a very trial and error process at this stage.
This is a better rendition of the yellow green color. The salt pulled the green color out of the dye and made a nice effect on the habotai (aka china silk).