After quite a bit of thought and fiddling around, I finally came up with a violet ice-cream recipe.  Not too much colour… very subtle flavour, most of it coming as an after-taste, like most perfumes  (think truffle, jasmine… an ethereal waft that floats between the nostrils and the tip of your tongue).

Violet Ice-cream

4 egg yolks
135g sugar
400 ml full cream milk
100 ml heavy cream, chilled
1 tbsp Monin violet syrup
1 tbsp violet liqueur (Creme de Violettes)
2 drops pink food colouring
2 drops blue food colouring

Heat the milk with half the sugar taking care not to let it boil.
Beat the yolks with the remaining sugar until the mixture is thick and white.
Slowly pour the heated milk over the yolk mixture, beating well.
Return the mixture to the saucepan and simmer, whisking continuously, until the mixture thickens slightly and coats the back of a spoon.
Make sure it doesn’t boil.  If you have a candy thermometer, the temperature of the mixture should reach 85°C.  Remove from the heat immediately. Stir well and add the chilled cream. Flavour with the violet syrup and liqueur and tint with the food colouring.
Cool completely and churn in an ice-cream churn.
Garnish with fresh or crystallised violets.