When we last discussed this someone on this forum mentioned they use "Green Spot" 30lb line. I didn't know what it was but found it online somewhere and got a 500yd spool quite cheap. It's white with green flecks; maybe trolling line? dunno but I like it anyway.
Yes, that's what I have. Not sure but I believe several companies make it. The spool I bought was from Cortland.
I've seen it with black spots too.