Looking at the some of [exotic] cables marketed out there, one see why the answer to above question is that not all cables will sound the same under DBT testing protocol.

For example, Silver speaker cables tend to be made of higher gauge [thinner] cables, or the silver Interconnect not having any Shields. If we compare them with standard speaker cable or ICs, one will probably note lower volume (especially in the bass area) for Silver, and higher noise or interference ratio for silver ICs.

Or, MIT cables have a secret patented boxes on their cables that will probably manipulate frequency response of the cable, and make them sound different than other cables.

And some cables are faulty by design such as Ribbon speaker cables that have excessive inductance (warm sound), or Silver/Teflon Interconnects that sound "bright" because of high frequency ringing due to undesirable properties of Teflon dielectric.

So if we do a round up of cables that are out there in a credible DBT test, it should no be assumed automatically that all of them will sound the same