I've had a quick look in "British Rail 1948-78, A Journey by Design" by Brian Haresnape, and the only BR catering items mentioned there are glasses and cutlery - nothing about crockery.
Regards,
John Webb
I can confirm from experience that there certainly was some BR crockery, issued for and used on the one time MotorRail service from Ely to Stirling and I suggest that it is likely there may have been others too.
However the stuff I recall was all plain green, but had a BR design number and double arrow logo moulded in the base of each item. (I have one complete individual tea-set today comprising one tea plate, small tea-pot (two cup size) and one cup & saucer.)
Perhaps there may have been other designs for more prestigious services
Plates, Mugs, Cups & saucers, Tea-pots & other tableware etc. were refurbished at Ely along with sleeper bedding etc. before loading the cars.
I recall a lot of this stuff being scrapped away from Ely stores to Cambridge in the early 1980s. (The ones I have were acquired somewhat later.)