I remember seeing kelly jordan coloring his line with a black marker at the bassmaster elite series potomac river event this summer. Anyone why he was doing this? on tv they just showed  a short clip of him doing it for a second while talking about how he flipps grass.

It looked as though he was using braided line, which after a while will tend to fade and become very light to white color.  He was using the black marker to make the line less visible.  A lot of people that us Hi Vis yellow braid for plastics and jigs will color the last 3-5 feet of line, they can easily see the yellow line but it is less visible to the fish.

As husker said, black is less visible in the water, and quite a few people choose to do this with their braided line. Some people also choose to cover their hooks in sharpie to prevent rust.  

Have you guys ever tasted one of those markers?  Yuck.  I can't help but think with such a distinct taste in the water the bass would quickly learn to avoid.  But it seams to work in at least some scenarios.

And if youare coloring your line think camoflage.

I've been doing it for a couple of years now.  I like clear line (CXX in Crystal), and will color it according to the water I fish, or sometimes not at all (I obviously don't color my fluoro).  Anything I think will give me an edge I'm willing to do.  I use Berol Prismacolor markers, which are fairly expensive for a marker, but the Prismacolors are the gold standard in colored pencils and markers (I used to take several art classes), and they have an awesome selection of colors...a TON of green and brown shades.  I have 3 I use; a light green, an algae colored green, and a light brown.  I'll get a pic up later; I'm on lunch.  The Prismacolors have two tips, and I just take the fat end and slice it with a thin fillet knife about halfway down.  Your line will go right in the notch, and I just run it up several feet above my bait.  

Have you guys ever tasted one of those markers? Yuck. I can't help but think with such a distinct taste in the water the bass would quickly learn to avoid. But it seams to work in at least some scenarios.

And if youare coloring your line think camoflage.

 Never tasted, only sniffed.  LOL

Have you guys ever tasted one of those markers? Yuck. I can't help but think with such a distinct taste in the water the bass would quickly learn to avoid. But it seams to work in at least some scenarios.TOO much time on your hands BTW you ever taste a manns jelly worm  pretty good ;D

And if youare coloring your line think camoflage.