Brian Sharrock wrote:

Germans had brown for earth!

No, the Germans used to use RED for earth. Add to that the fact that
red-green colour-blindness is quite common and the need to harmonise on
something other than the old British system isn't hard to see.
Apparently it took about 12 years discussion in CENELEC to reach
agreement on the brown-blue-green/yellow system -- and another 34 years
for the UK to come in line on fixed wiring colours! (But the IEE did
succeed in introducing grey as the third phase colour fx: cheering.)

--
Andy