Sources for sock yarn?

[bestjob]

I'm working on my first pair of socks and thoroughly enjoying everything except the colour of the yarn. You'd think that the only people who wore socks knit of single-ply yarn were very dull. Where can I get some spicy red or electric blue?

Also, ds is very sensitive to wool. He touched some very soft yarn the other day and said it was too scratchy. What can I use for his socks instead? Anyone know of a cotton/acrylic blend that is long wearing and still thin?

Thanks!

[LuvMy2Kidz]

I don't know how long wearing it would be, but I know you can get baby yarn that's really thin, and if you can find it in 100% cotton you could dye it in whatever color you want