Royal Signals Coloured FS cap

[milhistry]

I recently acquired this Royal Signals FS cap at a market. Not my usual field of collecting but it looked nice and the price seemed right too I assume it to be from the last few decades as it has staybrite buttons and a QC Jimmy badge.
I would however be interested to know when this style cap was introduced and also what earlier ones looked like. I've seen a few pre 1946 other ranks ones but not any officers ones. Were there embroidered versions of the oval pre1946 badge for example? Thanks