inside of bunker ie where the coal is painted gloss black, as is the outside of the roof. front of bunker inside cab black.
backhead of boiler painted black.
inside of cab including inside of roof same colour externally as cab so in the GWR era GWR green.
regulator lever vermillion/china red in GWR era. signal red in BR era.
reverser and stand black – but regional workshop variations so for example Caerphilly painted the reverser red!
anthony's query of a cream cab roof inside is a trick of the light in bob's excellent pics. (though if LT transport maroon inside of cabs were painted cream above waist height including inside of roof).
caution plate inside cab on fireman's side painted gloss black with lettering picked out in white.
cheers,
julian