But when they turn up, and their skin colour is apparent, the job turns out to have been filled.

ECONOMIST: Romanies

One is that the displays must turn from black-and-white to colour.

ECONOMIST: Electronic screens as thin as paper are coming soon

Although the voters of Illinois now seem to want to turn her out, Democratic leaders are not yet that colour-blind.

ECONOMIST: Illinois politics

Tiny particles of rock ground fine by the glaciers that feed it turn the water milky and give it this astonishing, alien colour.

BBC: A return to Middle-earth

No matter which initiative or investment they announce to great headlines now, many of the colour-coded graphs in this report won't take a turn for the better for a decade, perhaps two.

BBC: My big, fat Welsh annual report.

At this stage, however, using the protein that way could turn reading into a truly electrifying experience: a charge of about 4, 000 volts is needed to trigger the colour change.

ECONOMIST: Showing off