cleaning enameled jewelry

I have a small pin I've worn every day for the last few years. The surface is partly white enamel, and partly shiny metal. The enamel is starting to look kind of pinkish, presumably from dye transfer (I pin it to red sweaters reasonably often. And it's the red component that's most likely to leach out of brown or purple.) The surface is also looking generally scuffed. It's hard for me to see it as a velveteen thing. I'm afraid to use a jewelry cleaner on it, because they tend to be designed for just metal and gemstones. This pin has really enormous sentimental value, and I don't want to damage it. Any suggestions?