prince of wales ortho Cardiff

[nursesue]

I recently acquired a beautiful Cardiff set of badges belong to a Doris Mary Davies. What I thought was a reddish reflection on the Prince of Wales Orthopaedic hospital was actually red enamel I have a green version of this badge so am left wondering what is the significance of the red version? it's dated 18/8/54 - 30/11/56 so this would signify that the course was the 18  month ONC course taken pre SRN training Will try and upload a photo at a the weekend.