I like the yarn I spun from some bright blue/purple corriedale cross fiber I got at Webs in Northampton, Massachusetts. The shade of blue is a lot like bananas under UV light - wow! Check out http://www.newscientist.com/blogs/shortsharpscience/2008/10/why-do-bananas-glow-blue.html?DCMP=ILC-arttsrhcol&nsref=specrt11_pic
The yarn was spun on my Louet Victoria wheel, and plied on my Ashford traditional double drive. I plied it using the Navajo ply technique and it resulted in about 12 plied twists per inch in the yarn.