Hi Robert, I've not had much success with dark coloured boilies, I was at a lecture by Rob Hughes a while ago and he came out with the statement that Coots have taste receptors in their feet! Yep, I thought that was a wind up too but it is genuine. So no matter what colour your baits are the little buggers are gonna smell them. I've had takes from Coots in 20ft of water. What we have found is that they don't take kindly to a marker float whistling over their heads or being popped at with a catapult. Its something that we have to grin and bear i'm afraid, unless anyone else knows different.