A German road sign...

When the Germans occupied Guernsey there were no road signs so they found getting around the island difficult. So they used a grid of coloured routes; one more or less east to west; one more or less north to south and a ring road around the island.
When I was young they were painted on many road junctions but over time faded. All that is left of many is traces of yellow but a few have been restored like this one.