C300 has come to the rescue of Serbia and Montenegro's politicians.
At last a scientific answer to the political problems countries in the Balkans have faced for years.
C300 is a specific shade of blue which apparently keeps both Serbs and Montenegrins happy in the "flag battle" which followed the collapse of Yugoslavia.
The colour is a classic compromise - halfway between the Serbian dark blue, and the light blue of Montenegro.
The blue of the Serbian flag is darker...
The wrangling began when Yugoslavia was abolished in March this year, and changed its name to Serbia and Montenegro.
But no-one could agree on the new state symbols. Including the flag.
So the old Yugoslav tricolour continues to fly above state buildings while arguments persist over what colour blue the new flag should contain.
...than Montenegro's traditional shade
It's not as though Serbia and Montenegro doesn't have enough to worry about - the legacy of war, international isolation, and the extradition of suspected war criminals, to name just a few.
But this is what politics can be like here. Politicians argue over what elsewhere around the world might seem to be the most incredibly minor things.
Hence seven months of wrangling over the flag.
In the meantime the Yugoslav flag flies above state buildings
Just round the corner from the parliament is Belgrade's foremost flag-makers.
Here Zorica Alksic and her staff are still stitching together the old communist red, white and blue flag of Yugoslavia.
"Yugoslav flags still legally have to be flown outside federal institutions," she says.
"So we're still getting orders for the old flag. But Serbian flags for the republic are definitely our biggest seller now."
And it's not just the flag that needs replacing.
The old communist national anthem is still played at international football and basketball games.
When Serbia and Montenegro (and yes, people here think it's a mouthful too) played Italy in Euro 2004 qualifiers the national anthem was booed.
The money still has the old name on it.
The internet domain here is still .yu.
And then there's the passport.
At Belgrade's airport people pass through immigration clutching the old dark blue book with "Jugoslavija" embossed in gold on the cover.
As they queued up for the JAT flight to London (that's Yugoslav Airlines), I asked a few passengers what their country is called.
The first person I asked was caught completely off balance, and could not immediately reply.
I tried to put it another way. "When people ask you what country you come from, what do you say?"
"Actually I say Yugoslavia because nobody knows this new one."
Next to him there was a woman. "I try to say Serbia now," she said.
"Not Serbia and Montenegro?" I inquire.
"Err. Yes. Well I say I'm Serbian but I come from Serbia-Montenegro. Right."
It's all a bit confusing.
Professor Dusan Stojnov, a psychologist at Belgrade University reckons Serbia and Montenegro is going through a bit of an identity crisis.
"For many years people knew what it is to be Serb, or what it is to be Yugoslav. They even had some vague ideas of what it means to be European," he said.
"But at the moment they don't have a clue as to what does it mean to be a Serbian Montenegrin or whatever."
Most people, of course, have plenty of other things to be worrying about.
Unemployment here is among the highest in Europe. Wages are low. Costs going up.
And many know that in three years' time both Serbia and Montenegro have the chance to hold a referendum to leave the union.
So all this angst over the state symbols may be for nothing in the end.
At least C300 has come to the rescue over the colour in the flag.
Now all the politicians have to do is decide on a coat of arms. And they may only have three years to do that.