The former Lizzie McGuire star swapped her platinum blonde locks for an eye-catching aquamarine shade last month but that vivid green has begun to fade and wash out, it's left a subtle, lightly coloured look.
Hilary, 27, showed off her revamped hairdo on Tuesday (7 April) while taping an interview for US entertainment show Extra at The Grove shopping mall in Los Angeles.
She's been on the promo trail lately for her new TV show Younger, a comedy from the creator of Sex and the City, Darren Star. It's about a 40-something divorcee who struggles to find a job, so she undergoes a makeover, pretends to be in her 20s and lands a position at a big firm.
As well as acting, the star has also released a brand new single, 'Sparks', which is climbing the iTunes chart.
She tweeted yesterday: "#Sparks is number 36 on iTunes!!!couldn't be more happpppy what a great day!!! Love you guys for supporting me!! Let's get it closer to #1."