In a bowl mix together the soft cheese and icing sugar, until it is nice and thick.
Pour in the double cream, while mixing at a slow speed. The mixture should be thick and holds its shape.
Split the mixture between three bowls. Add a little of the orange food colouring to one bowl and mix. Build the colour up by adding a little at a time, mixing in between each addition until you get the desired consistency.
Put the cheesecake mixture into a piping bag with a large round nozzle.
Repeat, adding the purple food colouring to one bowl and green to the other.
Once you have all three colours in individual piping bags, pipe the first colour onto the top of the biscuit base. I went around the edges first before filling in the centre.
Using a spatula or palette knife smooth the cheesecake mixture.
Add the next colour on top. Again start by piping around the sides of the tin first and then filling in the middle and smoothing. Repeat using the final colour.
Put the cheesecake into the fridge to set overnight (or at least 8 hours).