I admit to being one of those saddo enthusiasts who like to know the obscure information - such as 'How many red 850R manual saloons were sold in the UK?'. It took some doing, but Volvo UK kindly sent me the following breakdown - enjoy!
One commonly held belief is that the turquoise cars were the rarest of all, but that isn't the case - its the white cars that are the rarest! And there were no white, manual 850R saloons sold!
Just a caveat about the above figures - although they have come directly from Volvo UK, I have no idea if this includes VIP/Military/Diplomatic sales - I suspect it is simply UK registration information? Also bear in mind that there are many imported 850Rs in the country, so if you do find a white manual 850R saloon, it isn't necessarily a fake - it could be an import ;)