Betty,
Just starting the bamboo journey. You can find the thread at some of the major tackle building distributors. Like Golden Witch, Anglers Workshop and the likes that have goods for bamboo rod building or restoration. If you cant find the color you need there are some classic antique rod merchants that also sell the genuine retro colors (pricy!). Hopefully some one else can chime in and list their websites.
good luck,
Seege