Thanks Andy! I did try green on black, it did look ok but I preferred the white plastic bit. For the white, I think anodized may be better combination than white on white. There’s really a lot of colour combinations that looked good. A built to order colour picker might even make sense.
I’m not a big fan of creating a proprietary cabling system. I see the cabling as an essential part of the function of the case. I’d need to have a physical prototype to judge how difficult cabling is. If it truly is an issue that needs to be solved with an accessory box, I might as well scrap the whole thing and go back to the drawing board. 
The way I intend the cabling to work is similar to the Apple G4 cube, you tumble the case over with the pipe acting as a hinge. From there you can pop in your cables.
With that said, it does look like there are a lot of solutions poping up for people that want to plug in a single cable. For example, some new monitors are coming with a single USB type C connections for the display stream, USB data and even enough power for a laptop. The display can then be daisy chained and have a USB hub built in. With a setup like this, it would be possible to plug just a power cable and a single USB cable to get access to your whole set of monitors and peripherals. Not to mention it would be easy to swap between your desktop and laptop/tablet.