DCLI - pink tinge

Had this DCLI for yonks, but only noticed today that there is a pink tinge to the metal showing through the plating where it has presumably been cleaned.

Others I have do not appear to be plated, with the metal in worn areas being the one colour ('white') and with no signs of this coppery stuff underneath.

Cornwall Ob.BMP.jpgCornwall rev.BMP.jpg

I have no idea if this is a good badge or not, and wonder if the discolouration is indicative of it being bad. Were DCLI badges ever plated?

With thanks,

Peter.