you'd have to create two separate ItemDatas and ImageDatas for both of them.
like:
SniperGoldItemData and SniperGoldImageData
its imperative that every color-swap you do is in its own folder. So you should have one folder that contains the sniper.dts and all the images and the gold ones, and then another folder with sniper.dts and all the regular images. then when you reference the model you do like
shape = "./GoldSniper/sniper.dts"; and shape = "./RegularSniper/sniper.dts"; for the other one