I couldn’t tell the difference myself, that type of tunnel roof lighting is used at numerous stations across the network. It could just be that the lighting elements themselves may have become dusty which would mute the lighting effect. It's surprising how much a thin layer of dirt like that can make a difference.
Child of Middlesex, student of the City, resident of the Metropolitan
Hello Tom 73. Regarding your question on the ambience of Notting Hill Gate station, I agree with you; the ambience is partly influenced by the colour-scheme of the platform side wall tiles, and of course the type of lighting. At Notting Hill Gate station platform vaults the wall tiles are of a very dark colour, thus light from the flourescent strip-lighting is absorbed by the dark coloured wall tiles. Whereas in the example of Lancaster Gate station platform vaults, these have white tiles which act as reflectors this deflect back any light from the fluorescent strip lights mounted on the ceiling.
Some stations do seem noticeably dimmer than others, especially on the central and jub. Hopefully as LED lighting becomes universal, light fittings can be upgraded to provide a higher luminosity where necessary to counter darker decor.