Am about to use black fondant to ice a birthday cake but am worried that kneading the fondant in icing sugar will make the colour fade. Will it be ok? Or what should I use instead to make sure it doesn't stick to the board?
You can do this and just smooth the fondant after it is on, as you smooth, the icing sugar will disappear. You only need to use a little sugar on the board to stop it from sticking. In an emergency, you can paint on a teeny tiny drop of water, but be really careful, because the colour will run.
I use silcone paper to roll out icing (sandwich the icing between 2 pieces) it doesn't stick to the board or the rolling pin. And easier to pick up, flip it over onto the cake and peel back while you smooth it through the paper.