That could be, but I don't know if they made badges with specialty branch backgrounds. I have not seen one.

CB

CB,
The badge with the purple backing to the anchor was in use between 1890 and 1918.
It was used by the following:
Chief Engine Room Artificer & ERA 1st to 5th class. (1890 - 1908).
Chief Engine Room Artificer & ERA 1st to 4th class. (1908 - 1918).
Chief Electrician & Electrician 1st to 4th class. (1906 - 1913).
Chief Electrical Artificer & Electrical Artificer 1st to 4th class. (1913 - 1918).
George

Thanks for that, I will have to look twice at some of my badges as I may have misjudged one!

CB

The various Civil branches each had a particular colour, but, only the Engineering branch PO/CPO wore it on their cap badges.