Brits: ID this blue alcoholic drink please.

Just finished watching the series “Black Books” (A sitcom about three chain smoking alcoholics). In the show, one of the characters is drinking from a tall skinny plastic bottle with blue liquid inside it. (I’d estimate the bottle to be about 12oz)
You can spot the main character drinking this in the series finale if you have Hulu.

Anyone care to take a guess?

Sounds like WKD Blue.

Haven’t got a copy ready to hand ( different HD ), but it might be Bombay Sapphire. Beloved since 1761…
Don’t care for gin at all; but saw it last night on a Touhou site — as Dry Zun — ! [ Zun is the demiurge of Touhou ].

Oddly enough that date is wrong — it appears on their website as such, yet Wikipedia has the venerable beverage going back all the way to 1987.
No doubt they mispoke.

Bombay Sapphire isn’t blue though. The bottle is. (ETA: Although I suppose from the viewer’s POV, it could be confused.) And I don’t think it comes in skinny plastic bottles.

Bols Blue Curacao?

I found the episode online, and it’s definitely the liquid itself that is blue, and it looks like it comes in a frosted/translucent bottle, maybe ten inches tall and two inches wide?

ETA: Here’s a screenshot.

Here’s another one. It looks vaguely familiar but I don’t know what it is.

Thanks guys. I tried to find a screen shot but couldn’t. Y’alls Google Fu is better than mine I guess.

To be honest, I don’t think it is a real drink. It might be water and colouring dye in an amusingly shaped bottle. Manny is drinking beetroot liqueur, which probably doesn’t exist - and Fran is drinking ‘Blurge’, which apparently seeps in through skin contact, and definitely doesn’t.

So this blue concoction is probably just a prop.