Sock yarn in English? Technical terms for English translations

Dear users, dear authors,
what is “sockenwolle” called in English? The literal translation “sock yarn / wool” doesn’t get me very far. Is there a specific term for it?
Is there a word in English for “Bobbel” or “gradient yarn”?
“Gradient yarn” = “yarn / wool with color gradient”?

I’ve already looked it up in the online dictionary. :-)

I found the following:

“sock yarn” and “self-striping wool” for gradient yarn.

I haven’t been able to find anything for “Bobbel” yet—except “cake,” but that doesn’t quite fit.

Now I’ve found “gradient yarn” for “Bobbel.”

I’m out of my depth when it comes to sock yarn—I’m afraid I don’t know much about it :)

For Bobbel, the terms I’m most familiar with are “gradient yarn” or “yarn cake.”

Both are also used in other contexts, but I think Bobbel are so well-known by now that people can make sense of both terms (especially in combination). 

Oh, looks like Marlene beat me to it.
Oh well—never mind, better to say it twice! :) 

Thank you both