Preheat the oven to 120’C (Fan 100’C) /Gas mark ½. Line two large baking sheets with baking parchment paper.
In a large grease-free glass bowl, whisk the egg whites until stiff and dry, forming soft white peaks. Whisk in the icing sugar, then using a large metal spoon, carefully fold in the caster sugar, a spoonful at a time until folded in and the meringue is stiff and glossy.
Equally divide the meringue between three smaller bowls and add a few drops of your chosen colours to each bowl, carefully folding in to make three pastel coloured meringue mixes.
Working on one coloured mix at a time, spoon the meringue into a large piping bag fitted with a 1cm (1/2in) star nozzle and pipe 5cm (2inch) stars onto the prepared baking trays
Repeat with the remaining two mixtures to make approx. 30 mini meringues. Bake in the oven for approx. 1 hour or until the meringues are crisp on the outside, but not browned. Prop the oven door ajar slightly if they start to discolour. Switch the oven off and leave the meringues to go cold in the oven. Store in an airtight container until ready to decorate.
Break the chocolate into a bowl set over a pan of barely simmering water and heat until melted. Remove from the heat to cool a little.
Place your chosen sprinkles into three small bowls. Working on one meringue at a time, carefully dip the bottom of the meringue into the white chocolate and then into the chosen sprinkles. Place the meringue back onto the lined baking tray to set. Repeat until all of the meringues are decorated then put aside in a cool place for about 30 minutes until set.