Italy: In search of orange

The Rainbow Hunters: One mother, two boys, on a trip around the world, to seven countries, to find the origin of seven colours

A Stradivarius is coated in flame varnish (AFP/Getty)

As we walk down the windswept Via Francesco Robolotti, the sounds of sanding, sawing, and chipping waft through the doorways of the violin workshops that line the street.

Here in Cremona, northern Italy, countless instruments have been made over the centuries, but the most famous were made by the Stradivari family in the 17th and 18th centuries. No one knows what makes a Stradivarius violin sing the way it does; some believe it's the wood and the cut Antonio Stradivari developed. Others that it's the Cremona varnish, flame coloured, bright as a tiger's pelt. The locals believe that once they discover the secret of the instrument's colour, they can master any song.

So it is here that the boys and I find ourselves in search of a sunset orange, with only an age-old recipe for cremona, dating back to 1747. Already we have got lost and been turned away from three workshops, and now we are standing despondently outside the Stradivari Museum, which is closed for the holidays. The boys press their faces to the glass, leaving smudge marks.

"You look for the Stradivarius?" an old man asks us, his eyebrows arched.

"We're looking for cremona," I tell him.

"Go to the pharmacy on Via Ceresole," he advises.

A neon cross flashes above a doorway. A short, bald man stands behind the counter. Tentatively I tell him of our quest, and he waves us out across a small courtyard and into a dark, pokey outhouse. Shelves, crammed with jars of aged amber flakes, powders of burnt yellow and red, liquids of rusted brown. It's like walking into the past.

Dow, my eldest son, places our order: a cup-full of shellac flakes, half of sandarac and some wine spirit. "We have to crush it and melt it over a fire," Dow reads from our recipe.

"Try a little of this, and some of this," the pharmacist says, reaching for a jar of amber, a jar of myrrh and ash. "And lastly," he adds, "you must listen to this."

The recording he plays us is Vivaldi's Spring Allegro, full of hope and celebration. "Perhaps," he says, "you will be the ones to discover the soul of the Stradivarius."

The Rainbow Hunters are raising money for War Child (warchild.org.uk; justgiving.com/ Lindsay-Hawdon) . To read more about their journey, visit therainbowhunters.com