Just received my grey Color Series HPC cable for my hd800 last evening.
The packaging, linen bag, business card and warranty card inside an envelope is simply 10/10, and the cable itself looks great
It's sleek, feels sturdy and doesn't really add any unwanted weight to the headphones like the stock cable did.
The nylon multifilament seems to prevent it from flexing too much, but not to the extent that it bothers me in any way.
hd800 plugs are even pretty well aligned with the socket of the headphones so that the cables don't brush up on each other or tangle after exiting the splitter.
As for the sound I'm uncertain if there is any difference between the Color Series HPC and the original cable and I'm unable to test properly as the stock cable has a short on the left channel
(the stock hd800 cable looks more solid than it really is, and the rubber started tearing under the leftside termination plug after 2 years of everyday use).
I can only say that the Forza AudioWorks Color Series HPC sounds awesome, and I've been listening to music nearly non stop all day.
Can absolutely recommend to others looking for a higher end alternative to stock cables for their headphones after seeing their craftsmanship firsthand.
I will most definitely order from Forza AudioWorks again if I need cables or recabling services in the future.