I depends what condition the surface of your calipers is.
The calipers I bought were the bare metal version. In Ti cars (ie: 159 Ti), they are of course painted red.
I cleaned mine with wax&grease remover, but isopropyl alcohol would be ideal. On areas of corrosion, I ground them back using a Dremel with a 'wire brush' attachment. If you have areas of corrosion, you can do the same; if not a Dremel, then a brass wire brush attachment on a power drill, like here:
http://pic20.picturetrail.com/VOL166/13 ... 791832.jpg (Bunnings sell them).
Otherwise, just sandpaper the paint (eg: 400 grade wet and dry then 800).
