Process the raspberries and sugar in a food processor or blender till smooth. Strain this mixture through a fine sieve and transfer to a large bowl. Add the sparkling water (mixed with the juice of one lime) and stir.
Process the kiwis and the other lime juice I the food processor until smooth.
To serve:
Pour equal amounts of the raspberry puree into each of 6 small, chilled bowls. Pour equal amounts of the kiwi-lime puree in the middle of the raspberry puree. It should now be red with the green in the middle. Put some of the honeydew and can'taloupe into each bowl and enjoy!