See: AVID RC

AVID have announced that they are revolutionizing the silicone wire game forever by being the first to introduce red shrink tubing for labeling those trick all black wire setups. Available in 4 thicknesses (14, 13, 12, and 10awg) as 1 meter long, it comes in any color you wish as long as it’s black, with 80mm red shrink tubing for marking your positive leads