An Egyptian women's rights group asked women to wear red and vote "no" in the referendum on a draft constitution written by an Islamist-led assembly.
Baheya Ya Masr urged women to wear red scarves and hang red towels or sheets outside their windows in protest against the constitutional referendum.
The group, that was founded four months ago to monitor the government's performance in dealing with issues related to women, said that the color red is known internationally as the color of protest.
It called for groups who wish to vote against the constitution to wear red to look distinguished and expose the reality of the referendum.
It also asked supporters of the cause to promote it through their Facebook profile pictures.