hotncold said:
help required regarding new telephone colour coding ( domestic), I have the old wires ie. blue, orange etc. how do these marry up with the new colours.
This is not a sensible question to ask because you should not need to know the answer, even if there was a reliable answer.
What are you trying to do? Wire up an extension socket?
If you have a main phone socket then it will either be a modern Linebox, or an old-style Master socket.
You can tell which one you have because a Linebox will have a horizonal line across the front of it between the two parts and the socket will be lower than the centre of the box, whereas a Master socket will have no line across it and the socket will be dead centre in the front plate.
If you have a Linebox, you wire extensions by connecting terminals 2, 3, and 5 in parallel between the terminals on the back of the Linebox lower front plate, and the terminals in the extension socket(s). (You might as well wire up terminal 4 because otherwise you'll have a spare end flapping round.) You are allowed to take the lower front plate off the Linebox, thereby disconnecting your premise wiring from the telco's (BT's) system. However you aren't supposed to take the entire front off, because this would expose the "live" telephone circuit (about 48V DC when quiescent or about 80V AC when ringing).
If you have a Master socket, you must use a wiring adaptor (a little thing with a plug on one side, a socket on the other, and a bit of cable coming out the bottom), and wire the extension socket according to the wiring adaptor's instructions. You're not supposed to take the front off the master socket, because this would expose the "live" telephone circuit. If you want to wire further extensions, you just wire them in parallel with the first extension.
If you don't have either a Linebox or a Master socket then forget it; you need to phone your telephone company (BT) and get them to put in a phone socket, which nowadays will be a Linebox.
Terminal 4 is not used on domestic installations and you only need to connect terminals 2, 3 and 5, but the conductors in telephone cable come in pairs and wiring up terminal 4 keeps the spare fourth conductor tidy.
If you are going to wire both ends of a bit of standard cable, and therefore get to choose the mapping between colours and terminals, then you should use the standard mapping:
terminal 2 : blue/white
terminal 3 : orange/white
terminal 4 : white/orange
terminal 5 : white/blue
Ultimately, you could use any colour for any terminal, as long as it connects the same numbered terminals together, but if you have standard cable you might as well use the standard mapping because it causes the least confusion and work for anyone else who comes along later.
Wiring information here:
http://www.telephonesuk.co.uk/wiring_info.htm