Margarita Bitters can be optional, but the flavour is much better if your include.
This can be made using all blue Curacao if you do not have Parfait...
As the name suggest, this Margarita does indeed have the hue the deep blue of the Pacific Ocean. On the sour side with hints of parma violet, rose and vanilla.
Simon, Thanks for your comments.
While I do like my cocktail more on the sour side, from your comment I did add 1/4 oz sugar syrup. I do think it makes it a more balanced cocktail.