Yes.Originally Posted by caesar
If its 4 core it goes on the centre 4 conductors, 6 core on the centre 6, and 8 core fills the plug
Just make sure that you get the two ends the same
That picture you showed uses the American line cord colours as far as I can tell as Red/Green is Line1, Yellow/Black is Line2 but I have never seen the "official" US colours (or should that be colors?) for lines 3 & 4
BT colours used to be Red, Blue, Green, White when all phones were hard wired but after PST (Plug and Socket Telephone) was introduced in 1981 there have been loads of variations as you never actually need to use the wires individually because you just crimp a plug on. I have seen Red with 3 whites similar to ribbon cable where the red just tells you which is the first wire. I have also seen cables with 4 transparent wires where the only identification was a rib on the underside of the cable.
In short, there isnt really a "standard" colour code.