7th and 12th Field Regiments RA signs?

[loupie1961]

Recently purchased on ebay, sold by guy who frankly admitted he had not a clue about what formation signs could they be.
according to Morris, formation sign of the 7th and 12th Field Regiments royal Artillery was a red "2" on a blue diamond, but when I have taken this pics, I have realized diamonds are unmistakingly black, therefore another formation? thank you in advance for your knowledge, gents!