A projection reading ‘Vote Remain’ that was first shown last night from 9.30pm, is one of a number of pro-EU messages that will be displayed on iconic UK landmarks ahead of the vote.
The Eiffel Tower, Warsaw’s Cultural Palace and Tate Modern in London are among the other landmarks displaying messages backing EU membership.
John Edward, senior campaign spokesperson for Scotland Stronger In Europe, said: “Scotland is stronger, safer and better off in Europe.
“A vote to remain is a vote for more jobs, lower prices, workers’ rights, stronger public services and a decent, tolerant country.
“Remain is the positive choice for Scotland and the UK as a whole.”
Edinburgh Castle itself is regularly lit up to support different campaigns and has been highlighted for St Patrick’s Day, the Stroke Association, solidarity with Belgium following the March terror attacks and as a tribute to the victims of the Orlando shooting.