Actually the third rail cover should be quite dirty and blend in
with the tunnel by now and I don't think that our tunnel is brown.
Actually you do not really need to use any tunnel texture just use
a dark background and make the track very dark and let all things
float on the air. Basically like this (though this does have a
think black wall but the author in its previous version did not use
any tunnel wall texture and even the track cause it is simply too
dark)

Than when approaching station a fade in effect can be and
probably only here a tunnel texture is needed.

The jubilee line also to me somehow look like our MRT tunnel
(newer section)

Generally our MRT system is similar to some system worldwide,
some have their own BVE 4 routes. I have use the Jubilee Line &
KCR West Rail for BVE4 (the one with ATO) for reference.
Me too. XD Well, I wasn't able to stimulate the headlights,
therefore i had to make it abit brighter.