13 Pounder 9 Cwt - Yellow base?

[Falcon]

I bought a 13 Pounder 9 Cwt case last week at Detling with remnants of yellow paint on the base, the seller said this was original. Is this correct?

Is there any official documentation as to the meaning of the colour(s)?

Thanks in advance for any info.

 

[doctor]

Hi
Yellow color is for an HE cartridge round
stencilled letters in Red

 

[Falcon]

Thanks for the info, there is not enough of the paint left for any stencilling to be visible, but nice to know it has some original paint still there.