Amanda Bynes shows off blonde hair on Twitter

Amanda Bynes is looking like her old self again.

Bynes, who was hospitalized under psychiatric hold last year, sparked concern when she was caught on tape talking about killing her parents and writing disturbing tweets. Since November of last year, Bynes has kept a low profile.

The former Nickelodeon star has only resurfaced very occasionally. She posted a few selfies in December and January, and tweeted a drawing she created in March. Since then, she has been offline. She made a public appearance at the end of July, and on Tuesday, she tweeted a photo of herself with a friend, looking happy and healthy.

Bynes sported a black dress and long, wavy, platinum locks.

"Me and the fabulous Michael Costello (I'm wearing one of his beautiful gowns) at the SOAR Los Angeles Gala!" she wrote.

The gala's event planner told People: "She was 100 percent in good spirits -- she's just a sweetheart. She had a wonderful time. Amanda supports the cause as well, so she came out with Michael for the evening and she was in great spirits. She enjoyed the evening with us and looked beautiful in her gown." SOAR stands for the Society for Orphaned Armenian Relief; their gala was on Sunday in Los Angeles.

Bynes, 29, remains under temporary conservatorship of her parents.