Why Blue? Because Deer See It Best. We didn't pick blue rope just because it looks good (though it does). We chose it because deer see blue more vividly than any other color, up to 20x better than humans. Their eyes are tuned to short-wavelength light, making blue stand out like a beacon in the wild. Bucks will deposit scent from their glands on low-hanging limbs by vigorously licking and rubbing to mark their territory with an unmistakable aroma. The Rope-A-Dope combo helps amplify the action! The special gel formulation of Rack Rub is long-lasting and provides smooth, even coverage on the included rope to help bring bucks into shooting lanes or in front of your Moultrie camera!