Fully coat the outside of your cake with buttercream and roll out your white fondant.
Using a small circle cutter (we use a piping nozzle) cut out lots of white circles from the fondant.
Using a small drop of food colouring of your choice (we used green) knead into your remaining white fondant until you reach a pastel shade. Roll out and cut out more circles of fondant.
Repeat this process with the remaining fondant adding another drop of food colouring to make it darker and cut out more circles.
Starting at the base of your cake begin to stick/position the darkest circles of fondant close together, you can overlap slightly if you prefer. Gradually stick all of the fondant circles on to the cake so that the colour gets lighter in an ombre effect. Top the cake with the white fondant.
For an added touch decorate the cake board with some brown sugar (to give a sand effect) and add seashells.