But on Thursday, social media users might be noticing that many of their friends, family and, yes, favorite celebrities have decided to "Light It Up Blue" as well. And it doesn't have anything to do with a paid music subscription service.
April 2 marks National Autism Day, and to raise awareness, Autism Speaks explains on its site, "Thousands of iconic landmarks, communities, businesses and homes across the globe unite by shining bright blue lights in honor of the millions of individuals and families around the world affected by autism."
And, of course, people on social media are participating by posting photos of themselves sporting the color and pictures of loved ones who have autism, all with the hashtag #LIUB.
Even celebrity ambassadors Ronan Farrow and Carole King are getting in on the action:
This blue definitely doesn't make you feel blue.