In the grand scheme of things, is the color code really a big deal? Probably not if everything is wired correctly. The relationship between older and newer wire pairing has been the same since at least the 1950's, if not even earlier.
I still come across people who are confused by the old British color coding here. Up until about 1980 the standard quad cable used by the G.P.O. for internal wiring was blue/orange/green/brown (not white/blue, white/orange etc.
pairs, just the four plain colors).
Four-conductor cable as white/blue & white/orange pairs came into use about the same time as our new modular-style jacks, and since it was only then that DIY phone wiring was permitted, most people today know little if anything of the old code, since it was rarely used on the customer side of the demarcation point.
I still find the old cable in use from time to time though, particularly where BT has since installed a new drop and master jack, then just reconnected old extension wiring and effectively given the old G.P.O. wiring to the customer. This is particularly so where runs between old junction boxes have been left intact and new jacks run from there.
The problem is that the packaged instructions which come with all the modern accessories just assume that W/B, W/O pairs are in use and make no mention of the old scheme at all. Unfortunately, even some people actually working in telecoms today don't seem to realize that the current color coding scheme only goes back about 27 years!
There was a thread on the IEE forum a couple of months ago in which somebody clearly had the old cable. More than once I pointed out that the standard was for the line to be on blue (ring) and orange (tip), yet others kept insisting that I was wrong and that the line would be on the white/blue pair. I'm still not sure I convinced them.
Just to add to the fun, we had a completely different scheme on the cord to the phone itself which used red/blue/green/white, with the line on red (ring) and white (tip).
Now, I have a question: Why do people think that they need to run CAT5 cable for voice?
Or even for DSL. I can
partly understand the non-technical people believing that, as they're just thinking "computer data," not realizing that DSL is
not the same thing as Ethernet.
I don't think some of the ISP tech support departments help. I just ran some extension wiring for somebody a few days ago who had been through this with his ISP when the guy there kept insisting that the DSL modem must be plugged directly into the first jack in the house, no extensions permitted. As if another 20 ft. is going to make any difference when we're already at the end of 5 miles of wire from the C.O.