Following my PA Christmas Cracker project I'd mixed up far too much GP as you do, so added some blue paint to the greens and put them through a couple of T!m stencils onto a large black tag.
I then sanded the whole thing back.
And finally added treasure gold and metallic pan pastels. Unfortunately this isn't a true representation of the tag, it's much brighter IRL but the weather these last couple of days has been so dark, wet and gloomy that I couldn't get a good photo. I tried using the daylight lamp but it was too reflective.