The "Ain't it Fun" singer followed the Twitter announcement with a longer statement on goodDYEyoung's official Instagram account on Saturday.
"I've never started anything but a band… but a little over 4 years ago, I decided I'd try my hand at starting a hair dye company," Williams wrote alongside a photo of herself with bright yellow hair. "I've made a lot of mistakes, learned a whole lot of cool business lingo… and realized through trial and error that dying your hair is an art AND a science. It was all worth it to finally be able to tell you that GOOD DYE YOUNG is here, it’s severe, & it’s happening! I can dye happy now!"
The dye line is definitely a passion project, as Williams teased Nylon with news of the hues back in 2014. "I’m sort of drooling over it, and I can't wait to show people," she told the magazine. "Obviously I'm not going to put out anything that I don't believe in or that I don't wear myself."
"The colors are wild and awesome," she added. "I really can't wait to paint everyone's hair in the whole world."
This isn't the first beauty endeavor Williams has dug her hands into. Last year, she launched the web series Kiss Off! with makeup artist Brian O'Connor.
It's been a very busy year for the rock star already. Last month, she married New Found Glory's Chad Gilbert in a private Nashville wedding. Watch the video below for all the details on her non-traditional "I do's."