Nup. It's those colours on the walls. Such subtlety, such elegance, such simple good taste. Suddenly rag-rolled terracotta and screaming cobalt seem violently intrusive, and dull old magnolia appears positively vulgar in comparison with elegant shades of stone, sand, pea green and biscuit.
There are now several companies specialising in "historical" colours. The lead-based paints that would have been used to cover the panels and walls of the formal rooms of Jane Austen's day are now banned by EC directive except for exterior use on some listed buildings. House painters tended to have rather a low life expectancy due to the build-up of lead compounds in their lungs when they were rubbing paint down to stop it being shiny. But, as the Wonderbra will produce the same sumptuous effects as the 18th- century corseting worn in the production, so many of the paint colours can be obtained in modern versions.
Many of the paints supplied to the Pride and Prejudice set designers came from Farrow & Ball. Their "dead flat" oil will achieve much the same effect as the old lead-based paints, while keeping the mortality rate down.
"The only shortcoming is that it is too good a paint," says Tom Helme, decorative adviser to the National Trust. "It contains titanium which covers very well. Under the old system, you would have had to build up lots of different coats. There are lots of 18th-century accounts of each coat being a different colour."
Farrow & Ball are also the paint suppliers to the National Trust, providing stately homes with colours such as Mouse's Back and the infamous Ointment Pink. The National Trust colours are toned down, so that the walls do not shout at you to the detriment of paintings and furniture. But the firm has just brought out a new colour card, expanding from the original 57 Trust colours to 95. The new colours are brighter than the Trust ones, and include some from the company's archives, such as Menagerie (an 18th- century terracotta) and Pale Hound (light yellow), and others that people have asked them to match during renovation.
But the new colours are far from garish. "Some people say, 'Oh, but originally the colours were very bright,' " says Mr Helme, "but they faded much quicker than nowadays. Those colours are encapsulating one teensy percentage of a house's time. People think paint analysis is scientific, but there is a lot of interpretation in it."
Although dead flat oil is perfect for displaying Canalettos and Gainsboroughs, Farrow & Ball also supply an estate emulsion for more general use. It is made up to an early formula and so is very flat. Modern emulsions are "too rubbery", says Mr Helme.
The other paint medium popular in the 18th century was distemper, though this would only have been used for hallways and servants' quarters in grand houses. It produces a lovely chalky cover which can be recreated by using a modern oil-bound distemper (again, Farrow & Ball supplies this). Nowadays it's suitable for farmhouses and cottages, but not for use in flats in smoggy towns, as it does not wash well.
As to the exact colours that were used in the 18th century, both Tom Helme and Gerry Scott, production designer on Pride and Prejudice are reluctant to commit themselves specifically, although the house painters of the 18th century would have been working within a fairly limited palate of earth pigments. "Houses were painted more frequently than we would imagine," says Mr Scott. "If the Bennets were fashionable enough to wear muslins, they were fashionable enough to have lighter walls." In other words, they would have painted the wooden panelling.
We would associate lilacs, greys, pale blues, pea greens with the eighteenth century, but, as Mr Scott points out: "If you wanted to prove a certain colour was used, you could. There's nothing neat about it ... it comes down to how you use it. If we put a piece of brown cord together with an orange carpet, we know exactly where we are."
Quite. A long way from Longbourne.
Farrow & Ball, Uddens Estate, Wimborne, Dorset BH21 7NL (01202 876141)