Blue Curacao

Curaçao is a liqueur flavored with the dried peel of the bitter orange laraha. It's been a popular liqueur for more than 150 years, the Dutch East India Company created this orange liqueurs by steeping orange peels in alcohol from the island of Curaçao and called it Curaçao liquor, unlike Triple Sec, Curacao has added spices and herbs to the orange and Curaçao comes in a variety of colours such as clear, orange or blue.

Blue Curaçao being the most used of them, in cocktails. Although Curacao is an orange tinted liquor, Blue Curacao is a regular Curacao dyed bright blue to give it a striking appearance, and thus is a very popular cocktail mixer, whenever a striking colour is desired.

Blue Curacao is usually around 25% ABV.

Blue Curacao is essentially Orange Liqueur tinted Blue, the colour doesn't influence the taste and thus Orange Curacao is interchangeable with Blue Curacao in recipes, if the colour is not important in the appearance.

NOTE: Blue Curacao being an Orange Flavoured Blue Liqueur, it's primary purpose in a cocktail is introducing the Orange flavour and the striking sky blue to the drink, so, if a bottle of Blue Curacao liqueur is something you are not planning to buy right now, you can manage with the Blue Curacao Syrup.
It would add the same flavour and colour profile to the cocktail, all we need to do is simply count for the alcohol absent in the syrup and account for it.

Southern Comfort

Southern Comfort is an American, fruit flavoured whiskey liqueur. Originally created by bartender Martin Wilkes Heron in New Orleans in 1874, the brand has gone through closure during the Prohibitions and transitions and transfer of ownership.

Spirit Historian Chris Morris describes the original recipe of Southern Comfort in an episode of The Thirsty Traveler titled "A River of Whiskey"

Heron began with good-quality bourbon and would add: An inch [2.5 cm] of vanilla bean, about a quarter of a lemon, half of a cinnamon stick, four cloves, a few cherries, and an orange bit or two. He would let this soak for days. And right when he was ready to finish, he would add his sweetener: he liked to use honey. - Wikipedia

In the United States, Southern Comfort is available as 42 US proof (21% ABV), 70 US proof (35% ABV), 100 US proof (50% ABV), and 60 US proof (30% ABV) in Australia. Varieties including additional flavorings, such as lime and caramel, were introduced by Brown–Forman in the latter years of their ownership. These were discontinued by Sazerac - Wikipedia

Grenadine

Grenadine is a common non-alcoholic pomegranate syrup with a characteristic deep red colour. It is a very popular cocktail ingredient, used for its pomegranate flavour and more for its ability to add a reddish to pink tint to a cocktail.

The name Grenadine originates from the French for pomegranate, which is grenade.

Grenadine is not subjected to regulations like alcoholic beverages are, and there are no region specific formulae any more, and thus manufacturers often replace pomegranate with blackcurrant juice and other fruit juices while retaining the same flavour profile.

Many producers now use artificial ingredients like high fructose corn syrup, water, citric acid, sodium citrate, sodium benzoate and food grade red colour along with natural and artificial flavours.

Sour Mix

Sweet and Sour Mix, also Whiskey Sour Mix or Margarita Mix or Daiquiri Mix is a versatile mix in many cocktails.
This is a yellowish-green coloured concoction, with equal portion of lemon or lime juice with a simple syrup. When this mix is shaken vigorously with ice it produces a pearly-white liquid mixture ready for your cocktail.

Sweet and Sour Mix, also Whiskey Sour Mix or Margarita Mix or Daiquiri Mix is a versatile mix in many cocktails.
This is a yellowish-green coloured concoction, with equal portion of lemon or lime juice with a simple syrup. When this mix is shaken vigorously with ice it produces a pearly-white liquid mixture ready for your cocktail.