In the wake of the attacks that shook Paris on Friday, the world rallied to show support for France. Facebook, for its part, is offering a custom filter to overlay profile pictures with France's national colors — blue, white and red. Here's how Facebook users who would like to show solidarity with Paris can get the filter. 

First head to Facebook's Products/Service page. In the post announcing the offering, click "Try It."

Users will have the option to overlay the filter onto their current profile picture or select a new photo to upload instead.

Next, Facebook will prompt users to set an expiration date for the overlay. The filter can be activated to expire in an hour, a day or a week. Users also have the option to apply the filter indefinitely, and can later remove it manually. Like any other photo post to Facebook, the offering give users a chance to add a caption. Many users on social media used the hashtag #JeSuisParis to show their support.

Users on Twitter used the same hashtag to show their support.

A sign in French reads "We are Paris."Source: Matt Dunham/AP
A sign in French reads "We are Paris."  Matt Dunham/AP