"Bought this to identify switch-drops rather than buy brown-brown cable. Yes - you can use it to mark a blue cable as live, but not easily. The blasted stuff really isn't sticky enough. It's nice and thick, not too stretch, comes on a nice big roll but just isn't actually adhesive enough to stick. Also - the colour is really very dark - far darker than the brown of most cable. If the lighting isn't good it looks more black than brown. What would be really good is if ScrewFix sold brown sleeving at a reasonable price."