Fondant icing is most commonly used for wedding cakes. The super sugary and thick icing allows cake decorators to mould any shape or design. Fondant can be pretty tricky to make at home, especially if you're not a baker, cake maker or cake decorator by trade. But you can purchase premade fondant from local bakeries, cake shops or speciality grocery stores. The thickness of fondant makes dying it at home a little difficult, so instead of kneading in food colouring, simply "paint" the fondant with gel colouring.
Place the fondant on a clean, dry surface.
Roll out the fondant with a rolling pin. You will want the sheet of fondant to fit over and around the entire cake, so roll out the fondant to be as thin as possible without tearing it.
Squeeze tubes of gel colouring onto a paper plate. You can find gel colouring tubes at bake shops and grocery stores.
Dip a paintbrush into one of the gel colours, and paint the colour onto the fondant. Use a thin brush for writing, a medium-size brush for doing designs and a large, flat brush for such shapes as flowers and leaves or for coating the entire fondant.
Allow the gel to dry for an hour before serving.
If the gel is too thick, add a tablespoon of vodka to it to thin it out. The alcohol will make the gel easier to paint with yet not ruin the fondant. Never add water to thin out the gel. Water will ruin the fondant making it sticky and hard to use.