It's for use outdoors for portable appliances, mainly power tools - it's made to remain flexible down to -20°C, hence the name (long before which though the British nancy-boy tradesman will have given up and gone indoors, unlike his manly Siberian colleague who'll still be stripped to the waist saying "phew, what a scorcher".....
).AFAIK the convention is yellow for 110V and blue for 230V, but both cables are identically rated.
