Many cocktail recipes involve grenadine syrup. This is a NON-alcoholic substance that is just a fruit mix, really it primarily adds color to your drink.
What is grenadine made of? Traditionally it's made from pomegranate, which is a red, tropical fruit. Think of it as a very red peach. Depending on the quality of the syrup you get, it might just be sugar water with red food coloring. Sometimes they toss in raspberry juice for flavor or color.
If you want to make your own, it's really easy. Blend up some pomegranates (without the seeds, unless you like your syrup crunchy). Add in some honey, maybe 1/4 up for 4 whole pomegranates. Voila!
A pomegranate is about a banana in terms of carb count. That is, it's high, but it's not sugar :) So you get about 25g of carbs per fruit. Now of course, when you make cocktails, you're not eating entire fruits. You use a dash or two of grenadine to give the drink a red color. There are many Champagne cocktail recipes that involve "a dash" of Grenadine.
You can even use low carb honey, if you want, to further eliminate the tiny amount of extra carbs.