NEC wouldn't apply to telecommunications/low voltage.  You may think yellow is common because of single mode fiber.  Gray is far more common in the field in/on buildings.  OSP is usually orange, because orange is the color for telecommunications/phone/internet.  Gas plants use yellow markers/tracer.

On Thu, Dec 5, 2024 at 4:42 PM Gary Buhrmaster <gary.buhrmaster@gmail.com> wrote:
On Thu, Dec 5, 2024 at 8:15 PM William Herrin <bill@herrin.us> wrote:

> As others have noted: conduit is smarter. Communication cable
> standards remain in a state of flux much more rapid than the lifetime
> of a house and the little blue one-inch conduits are not exceptionally
> expensive.

And electricians (and the inspectors) understand
ENT(*) and it's installation requirements (yes
it still has physical securing requirements,
such as securing it near the box, and at
regular intervals along its run).

All in all, for a new construction, I would
require it all to be in ENT.  But, of course,
a builder looks only at the lowest cost(s),
as (probably) 98% of the buyers only look
at how pretty the stainless steel appliances
look like in the kitchen (surprise, surprise,
those participating on the list are not the
normal house purchaser).

Gary


(*) Commonly called smurf tubing due to a
manufacturer's choice of blue, but it does
come in other colors, and I think technically
communications are supposed to be yellow
per the most recent NFPA 70 (aka NEC),
but I am absolutely too lazy to review the
latest regulations.