By the 16th century, oil bases and, later, a growing understanding of colour allowed for ever subtler combinations.

ECONOMIST: Science and history of colour

And although the latest conflict was triggered by Georgia, the deeper roots of Russia's invasion lie in domestic events that go back as far as 2003-04: the destruction of the Yukos oil company, and Russia's perception of the colour revolutions in Georgia and Ukraine as a Western plot to undermine its sovereignty.

ECONOMIST: Russia and Georgia

Delacroix used the traditional genre of flower painting throughout his career to examine form and colour, and both his small studies of delicate irises and jasmine as well as large oil paintings of carefully composed floral still lives are on show.

BBC: Paris�� art world is in full bloom