I have a vague recollection that some cabs may have been repainted in the cornflower blue used in D78 cabs. Or was that done to all 67TS on refurb? Not sure about console indications. Perhaps a trial of LEDs replacing filament lamps? Perhaps this will jog someone else's memory.
I do recall some cabs being painted to a off white/cream, dark blue rather than the traditional light grey, on Refurb they were all painted in the cornflour blue, At this time a number of lines (northern 59's were also experimenting with interior colours, so think these were trials just to get operator approvals for different colours. Cab roof panels were also painted white internally to help reduce cab temeratures, and improve the ambience.
The cab indication lamps were origially bulbs within the black console panel, which were just plain bulbs with the console being the colour for the visuals, I seem to remember some MA indicator lamps being replaced with larger raised orange indications at some point, the code visuals were always quite poor to see, and think that some of these may have trialed new lamps, but effectively the drivers console indications and panel remained the same and were not changed.
Consol lamps were white light,the lamp holders originally had slot screw tops which quickly became distorted which made them difficult to remove.They were later replaced with holders with gnurled tops which made it easier for changing lamps.