Pronouncing your User Name may be harder than answering your questions.
No, the Copper Venom is not Frank's newest cable. It came out about the same time as the Silver Poison, just before the Silver Venom, if memory serves.
Balanced wiring tends to sound quieter than single-ended wiring. More important, balanced outputs from amplifiers tend to have more gain than SE output from the same amp, which is what you need with power-hungry ogre like the Hifiman HE-6, not so much with the Sennheiser HD-800.
The gold-plated plugs work fine with copper wires. The silver pins seems to help if you use silver wires. Well, they cost so much it helps ease the pain to think that they sound better....
As to which wires, silver or copper, work better, I would answer by repeating what I wrote quite a while back:
... Silver (or high skin-to-volume ratio litz cables) allows better high-frequency transmission which results in better treble reproduction, more details, better sound-stage and tighter bass. Often this sound could appear (pardon the poor choice of word) to be more detailed but brighter and thinner. I would like to add two important points in selecting the right cable for the headphones
First, its is not a simple matter of accuacy or quality, but also that of sonic matching. I found to the detriment of my pocket book that the most accurate--or arguably the highest-quality cable--is not always the best cable for all headphones. Quite the contrary. The underlying assumption here is that our headphone are perfect and accurate tranducers (sound reproducers). In most cases, that's far from true. The HD800 for example, one of my favorite pair of headphones, throws an amazingly large soundstage in addition to great inner details and a very tight and deep bass. Alas, the upper registry suffers from a very iiritable harshness and sibilance. I found that silver or silver/copper cable exacerbates these flaws and make the headphones sound not only overly bright but also thin as though there is hardly any bass at all. On the other hand, when coupled with an arguably less accurate or, as you apty put it, more colored copper cable such as Frank's Copper Venom, you've got...pure magic. The sound stage remains quite wide but the sibilance and harshness all but disappear and the bass becomes fuller, more impactful and still quite taut. In a nutshell, we should not select the best or most accurate cable but the cable with the sonic characteristics that best complement those of our headphones. With Frank's cables I found that the best matches are: HD800/Copper venom (no silver please); LCD2-3/Silver Poison [or Silver Widow]; HE-6/Copper Venom.
Second, the matching is even trickier than I just described as it goes beyond the cable because after all we listen to the whole audio system: DAC/amplifier/cable/headphones. It is the sonic characteristics of each component, link in the chain if you will, and how they interact with one another that determine the final quality of the sound we hear. While the way the amp, cable and headphone sound separately and generally (with a variety of systems) are good starting points, the final combination could still surprise you. I'll leave the discussion of the amp selection for another place and time.
I hope this helps.
I tell ya, you can add the Bayerdynamic Tesla 1's to that 'ogre power hungry list.' Close to a 1000 OHMS!! Man. XLR is almost mandatory for those cans. Lol