What strings have red silk at the headstock?

GHS Boomers do.

 

Thomastik

 

the ones that come stocked on a flea bass

 

rotos and certain set of labellas also have red silk

 

Are there silks at the ball end?

 

Based on the other criteria, those would be Boomers for sure.

If it was just red silk, all of the other suggestions hold true too.

 

A great place to buy them:
https://www.bassstringsonline.com/Bass-Boomers_c_169.html

 

Excellent! Let me know if there are any problems or issues, otherwise enjoy!

 

Rotosound Swing Bass 66 (RS66LD) 45/65/80/105 has red silk on both ends.

I just restrung one of my basses with them yesterday

 

Boomers are always the answer!

 

Labella 760FL (flats)

 

Really? I know that they've always had red silk, but the last two sets I've bought no longer have it.

 

Confirmed. Still red silk on their SS rounds as of this past month. What kind did you get that was without?

 

In addition to everything else mentioned...Ken Smith Burners have red silk with blue at the ball end.

 

The same. The first time, I had them put on when I got my bass setup about 10 months ago, and I thought the tech had put the wrong strings on because they didn't have the red silk. He assured me that he put on the right strings. But this last time, I bought them at the GC in Montgomery, AL, and took them right out of the package myself. . . . and I promise you, they were RS66 Stainless Steels. The same gauge you mention. No red silk.