Yes, hi viz yellow knife for best visability on the bottom. The key reason why the yellow handles are used on all of these knives. Products - Sturgill Spearfishing
Why do you think most dive lights are yellow? Why are cones, saftey vests, and school zone signs colored the way they are? For the hi visability.
I know I and many other people have lost knives after I dropped them and couldn't find them in the murky water. Sure is nice to be able to see your knife down there and be able to dispatch your fish after you retrieve your knife.
Yellow and white are 2 very high visability colors, I only use white or yellow floatlines because they can be seen by dive buddies so they know where I am at or by boaters hauling butt around dive spots. I have heard of spearos being drag around after a prop wrapped up their floatline.