Sorry, I'd forgotten that in the UK, all the fixed wiring cables are grey sheathed.(AFAIK)
Not exactly true, Twin & Earth which is used for most domestic wireing is usally grey on the outside, it was available in white as well, but as part of the colour change white T&E is the special low fume stuff, and grey is the normal stuff
years ago VIR (rubber) cables were used which were black on the outside, some modern cables are black, split concentric and SWA (steel wire amoured) are both black.
MICC can be bare copper on the outside, or can be white, orange, black, and probably many other colours besides, and firetuff is usually red (used for firealarms, so it can be seen at a glance what its for)
Different types of cable used in the UK can be seen here:
http://www.tlc-direct.co.uk/Main_Index/Cable_Index/index.html
