Preheat the oven to 110˚C (90˚C fan assisted oven, 225˚F, gas mark ¼). Line 2 large baking trays with baking parchment. Make up the Egg White Powder by empting the three sachets into a large, clean bowl. Add 6 tsps of warm water and beat well to a smooth paste. Add another 12 tsps of warm water gradually and beat well to form a smooth mixture.
Whisk until very stiff and dry. Whisk in the caster sugar a little at a time, to make a thick, glossy meringue, then gently mix in the Lemon Extract.
Spoon 3 heaped tablespoons of meringue into a small bowl and gently mix in 25 drops of Yellow Gel Food Colour. Divide the remaining meringue between 2 bowls and colour one with 25 drops Pink Gel and the other with 45 drops Violet Gel.
Spoon the pink meringue into an uncut piping bag. Using scissors, snip away about 2cm (3/4inch) from the end of the bag and then pipe 6 blobs in a circle to resemble flower petals, about 9cm (3 ¾ inch) diameter on one of the trays, spaced a little apart. You may find it easier to trace flower shapes on the parchment to use as a template; turn the parchment over in order to avoid transferring pencil marks to the meringues. You should be able to pipe 4 pink flowers in this way.
Repeat the flower piping using the violet meringue on the other tray to make another 4 flowers. Once the flowers are piped, carefully pipe or spoon yellow meringue in the centre of each using a teaspoon.
Bake the meringue flowers in the oven for about 2 hours until the meringues are crisp and dry and still perfectly coloured with no browning – prop the oven door open slightly if they start to discolour. Transfer to a wire rack to cool. Your meringues are now ready to serve and enjoy!