if that's not a contradiction in terms! I'm looking for a frosting that can be piped and will hold it's shape, and can be coloured, but it must last a couple days too! I don't mind if it contains a little fat (NOT CRISCO!!!). I tried mixing some powdered sugar with low-fat (35%) margarine, with 3 times it's weight in sugar, but it's just runny and horrid! Any ideas anyone?!

A meringue icing would work (not the buttercream meringues) Martha Steward had a cake covered in piped meringue. The cake was strange, in my opinion, but it showed that the icing worked great. color and flavor would be a snap.

Your basic "7-minute frosting" is fat-free as it is just meringue and sugar. cooked on the stove top over a double boiler for "7" minutes as you are beating it.

Here's a link to a similar frosting in the recipe section. http://www.cakecentral.com/cake_recipes_id-add_box-749.html