Here's the most successful result from my snow dyeing session. Essentially this is the typical tie-dye spiral with three colors: blue, red and yellow. However, I did not use primary colors, I used Dharma dye mixes for each of the three colors. And the snow works to slow the dye process so some of the dyes within the mix strike faster than others. And that's what is giving such color variation.
Here is a close-up. Fascinating! I arranged the cloth on a plastic egg carton and then added about a 2 inch layer of snow. Next I sprinkled the dye powder directly on the snow. (Health savvy dyers use dye concentrate--dye prepared in liquid to avoid air borne dye dust.) Then to demonstrate my own safety approach, I then added another layer of snow on top of the dye powder.
Unfortunately, the snow was less than cooperative. When handled it collapsed into itself like cotton candy. I thought that the extra layer of snow would contain the dye powder, but I was very wrong. It turned into such a fiasco I just left the whole mess in the unheated garage for a couple of days until I could face it again. Another innovation! Please see the Vicki W. tutorial to do this technique correctly.