A young Englishwoman flew into Afghanistan last year, wrapped her face in a scarf and set out in a Russian jeep for the mountains north-east of Kabul. When the jeep broke down, she travelled the last 40km up steep, rocky roads on donkey and foot, despite dysentery and a flapping boot heel. She was just one of many intrepid foreigners in Afghanistan as the Taleban hold on the country began to crumble. But this woman was on a unique mission.

Victoria Finlay brushed aside danger to visit the lapis lazuli mines at Sar-e-Sang, the world's main source of the deep blue stone and the expensive ultramarine pigment valued by artists since ancient Egypt's tomb decorators.

Fascinated by a Michelangelo painting that was left unfinished because the artist could not afford ultramarine paint, Finlay doggedly followed the colour to the inaccessible blue-flecked rocks. She was believed to be the only woman ever to go there, much to the miners' excitement. Her curiosity also took her to the giant Bamiyan buddhas, months before they were notoriously destroyed by the Taleban. The ultramarine frescos around their heads, painted about 1,400 years ago, were the earliest recorded use of lapis lazuli.

This is just one journey in Finlay's extraordinary itinerary for Colour. Structured as a rainbow, the book has a chapter on each of the seven colours of the spectrum, preceded by the equally important ochre, black and brown, and white. Each combines her extensive reading in history, science and culture with her own adventures, interviews and speculations.

The result is one of the more vivid in the fad for narrative histories about niche subjects (Rubble and Scurvy are two other new titles). There are many previous books about colour acknowledged in Finlay's impressive bibliography (oddly, she missed, or dismissed, The Primary Colours by Alexander Theroux). And there have been whole books on individual colours, such as Simon Garfield's best-selling Mauve.

With her zigzagging travels and jumble of anecdotes, Finlay has enough material for several books. Sometimes she has trouble keeping her narrative organised and might have benefited from discarding material. The most enthralling chapters are those, such as Blue, that focus on a single pigment. However, it's hard to criticise her spirit of cultural exploration and easy to share her intelligent enthusiasm.

There is plenty of amusement. She travelled to an Indian village to investigate a story about a brilliant yellow made from the urine of cows that were fatally fed mango leaves. None of the locals spoke English or knew anything about the cows, but they enjoyed her bovine drawings and her miming of urination.

Colour is packed with pertinent trivia, from the red that faded out of Turner's landscapes, to the reason Brazil is named after a kind of wood. There's the drama of pigments that proved unstable, ruining artworks, or poisonous, killing the people who worked with them. Messing about in the paintbox with Finlay is informative and fun.