I had black labella tapes on my fretless carvin, which is now sadly gone. The "white" tapes are on my new cheapo yamaha fretless and they are definately brighter. (Had them on my fretted Carvin but just got the yamaha so I wanted to try them on fretless) They do seem like a different material. It's hard to describe really. They kinda feel like super smooth plastic. They're smoother than the blacks which are already very smooth. Maybe it's because the black tapes were older, they had a shine to them, and we're just a teensy tine bit sticky. Their "white" tapes aren't the least bit clicky and work fantastically well on my fretless yamaha. I set the action super low so unplugged it buzzes quite a bit, but it's a mwah machine amplified with no unpleasant buzz or click, just singing.