Learning about ancient dyes for fiber is pure joy! I've been using indigo dye for many years--my first attempt at indigo dyes was with a good friend, who was also a botanist. We made up an indigo vat and had a good old dyeing day with fellow guild members. Later in my learning journey, I was education coordinator on an indigo plantation, which grew the plant for several years--an outlet for my dyeing ability to improve.
Recently, while surfing the web, I came across this wonderful video on ancient dyes.