Yea I could see where Black colored ones would be of use. You guys that know me, know I like Black. Like Antennas and trim tabs and such.
You have to usually sneak up on the size hole you drill thru the rubber. I actually have notes on the shop wall for what size drill bit for what cable.
See if you used a vernier caliper and measured the cable and then drilled the hole that size you would think that it would be correct. It's not because your drill rubber and rubber tends to stretch and push out of the way when you drill it.
So you end up with a hole to small. That's when you have to keep sneaking up on the size, but not go overboard.
Then once you think you have the correct size, you slit the rubber from the outside edge to the hole you drilled.
Now once you do that slit, it's about impossible to go back and drill the hole again if it's to small,as the rubber will just expand and no material will be removed.
So you do your damnedest to get it right the first time and thus why I have notes on my shop wall.
Something else when I drill the hole thru the panel that these are mounted on. As I said they are available in 3 sizes. Always drill the center hole as large as the gasket center hole.
This will help in the long run.