marked fishing line

Question
I just started to ice fish for kokanee this year.  And the fish are depth sensitive.  A few of the older guys have marked fishing with a color for each depth.  Like red for 5' and green for 10'.  They bought this line years ago.  Can this kind of line still be purchased and where?  

Thanks for your help

Answer
I did a rather extensive search for lines like this and did not find any. Cabela's has a trolling line that is wire that is marked.. but you do not want that I am fairly sure. I do know that Triple Fish makes a Camo fishing line. Several colors each different in sections.. but the color is so light you can not see it. I am looking at some now. It comes in such small diameter, that the color is not visible. I would try the following. Take and mark your line every 5 feet with a RED marking pen. One that is indellible. Red shows up less in water than other colors and disappears in dark colored water. Since you are Ice Fishing you should only need to mark about the first 30 feet.. UNLESS you are fishing deeper. Most lines are so small in diameter for ice fishing that finding colored line that you can see is going to be tough.. so my only idea is to mark it yourself.
I wish I could tell you where to find that line. I can not find anything like it in my materials.
Current Nylon lines marked with a marker may actually serve you better. Especially since you can pick the colors and use Flourocarbon which is invisible much more in water .. which allows you to use larger diameter.
Jim Dicken