I worked on that coaxial tap in my early days as an engineer at AMP. I remember them well. You had to use a cordless drill to put a hole in the cable so the probe would make contact with the center conductor. We have come a long way!
While Ethernet cables now come in all sorts of hues, their OG coloring was all bright and flashy in wild yellow. The color was chosen to both match the standard co-creator's furniture preference and prevent potential electric hazard.