I have a commission that I will be using a tapestry structure and wool for. There are some very large areas dedicated to a single color and I would like to dye the wool in "controlled and subtle" variations. I know how to make multi-colored designs but would love tips on making subtle but controlled changes within, say, rust skeins. I see beautiful examples on Etsy and Pinterest and am wondering how they control the subtleties. Any suggestions would be very much appreciated.