Stir the orange zest and liqueur into the praline base. Roll out the mixture between two layers of cling film in a rectangular shape about 2 cm thick. Chill for about 1 hour.
Chop both types of couverture separately and melt in a hot water bath. Cut the praline plate into about 15 pieces. Dip the pralines into the white chocolate coating using a fork (e.g. praline fork) and place them on a cake rack.
Pour dark chocolate coating into a disposable piping bag and cut off a small corner at the bottom. Immediately spray the dark chocolate coating onto the chocolates in strips and pull through with a wooden skewer to create a pattern.
Chill the chocolates for about 30 minutes.