Why are armoured cable colours different from twin and earth?

[joe90]

2 hours ago, HughF said:

tend to use 3 core (in the correct colours),

I just looked and screwfix only sell in grey,black,brown colours 🤷‍♂️

[HughF]

2 hours ago, joe90 said:

I just looked and screwfix only sell in grey,black,brown colours 🤷‍♂️

Yeah, I buy all mine from the electric cable co….

[Mattg4321]

5 hours ago, HughF said:

I tend to use 3 core (in the correct colours), then earth the armour at one end only, for protection and export the earth to where I'm going. If that's not appropriate and I'm making a TT island then I'll still earth the armour.

Why would you only connect the swa at one end if exporting TN earth? Both ends is a better job imo and keeps your Zs down.