Steam loco lamp colours

[mcjlf1]

Hi All,

 

Does anybody know of a reference or have definitive knowledge of the issue of loco lamp colours?  i.e. is there a 'correct' colour of lamp body for a particular company/era?

 

For example, I understand that LMS lamps should be black bodied, and the photo record generally seems to confirm this, as it does that BR(M) appeared to migrate towards using white bodies (but in some cases black lamps seem to have been used quite late on into the steam era).

 

I think SR and LNER lamps were always white bodied?, and then of course there is the GWR with their red lamps.  Is there any 'correct' time span for these? Was is a GWR only thing or did it live on into BR(W) days? 

 

Just wondering if there is a reliable answer to which colour applies to which company and/or period?  It seems to be a bit of a minefield.

 

Thanks in advance for any light which can be shed...

 

James