You can colour icings with any food dye; however, food dye is generally sold in packs of red, green, yellow and blue. While you can mix these colours to produce a gold colour, it will not have a metallic sheen. To achieve a metallic gold, you must use speciality products. Whatever your desired effect is, there are certain procedures and speciality products that can help you achieve the perfect shade of gold for your icings.
Purchase food dye from a speciality baking shop, craft store or an online store. Because gold is a difficult shade to achieve, you will need shades other than the standard colours that are sold in grocery stores. To create different shades of a nonmetallic gold, purchase the following colours: leaf green, golden yellow, brown, lemon yellow, orange and Christmas red.
Mix the lemon yellow, orange and Christmas red food colouring into your bowl of icing to create a basic gold. Sugar Craft recommends using 10 parts lemon yellow, 3 parts orange and 1 part Christmas red. Stir well until all colours are mixed together evenly.
Create an antique gold colour to add a richer and more tarnished look by mixing leaf green and lemon yellow. Stir the lemon yellow into your icing and add just a touch of leaf green until you have the desired colour.
Mix lustre dust with a small bowl of lemon juice, vanilla extract or vodka. The gold dust cannot be mixed with water or directly into the icing. The more dust you add, the more metallic the sheen will be.
Stir the dust and liquid together until the mixture resembles a watery paste. Mix it thoroughly so there are no clumps of gold dust.
Paint the gold mixture directly onto the icing on your pastry, cake or other baked goods. Make sure that the icing has cooled before applying the gold sheen. If you desire a more metallic look, apply multiple layers of the gold mixture.
You can use the golden lustre dust mixture to paint designs onto your icing-coated baked goods.