ProGel Concentrated Food Colour Multi-Pack Rainbow Dust ProGel are professional gel food colours that are highly concentrated, so you only need the smallest amount to give a deep, rich colour to your bakes.. ProGels are ideal for use with sugarpaste, royal icing, marzipan, cake batter, and buttercream. When colouring, add a tiny amount and gradually add more if required to obtain a deeper colour. Be wary that colours usually darken on drying. Each pack contains: Baby Blue, Black, Lime Green, Red, Yellow and Pink