Demi Lovato has gone back to blonde!

The "X Factor" judge showed offed her lighter, shorter and straighter locks at the 2013 National Children's Mental Health Awareness Day in Washington, D.C., on Tuesday -- the same day that she began streaming her latest album, "Demi," online ahead of its May 14 release.

Lovato, 20, was in D.C. to be honored with an advocacy award from the Substance Abuse and Mental Health Services Administration, for speaking out publicly about her struggles with bipolar disorder, as well as drugs and alcohol.

While she's rightly earning raves for her good work, Lovato also should be recognized for her tresses, which she changes often.

In the past year, she's dyed her hair dark red, rich brown, and blond, and has added streaks of pink, green, and blue. And yet, somehow, despite the frequent color treatments, her hair always looks glossy and gorgeous.

So we want you to tell us which color do you like the best? 

Photos courtesy of Splash News