Do blondes have more fun? It’s a yawn-inducing question, but Allison Williams reckons she knows why everyone’s so interested in the answer.

The actor shot to fame as Marnie Michaels on HBO’s Girls and, for many fans, became indistinguishable from the uptight, self-obsessed, judgemental and, let’s remember, fictional, character.

So with the final series fast approaching its last episode, the Get Out star decided it was time to change up her look. Cue her visiting her hairdresser and asking for her brunette locks to be dyed a new bright blonde hue, which she unveiled two months ago on Instagram.

“Here it is IRL,” she said of her blonde shade. “Still getting used to it, but I dig it. Thank you @auracolorist and @rebekahforecast for helping me say goodbye to Marnie — and to @allure for the nudge!”

However, during a recent appearance on The Late Late Show with James Corden, Williams admitted that it’s taken her a while to get used to her new locks.

In fact, the 28-year-old has found the entire process “exhausting” – and not least of all because people’s perceptions of her have changed along with her hair colour.

Read more: This is a girl's world: Stylist finds out why Allison Williams is nothing like her Girls persona Marnie

“Do blondes have more fun?” asked Corden.

Williams opened her mouth to reply, and then, looking exhausted, closed it again. After a few moments, the frustrated actor said “everyone keeps asking me that”.

“People keep asking me that and I finally realised that they’re asking it because they’re hoping I’m more fun now,” she said. “That’s definitely why. Even my friends and family are like, ‘Are you having more fun? Is this going to be a more enjoyable relationship for us? Are you also more fun?’

“And the answer is no.”

Williams continued: “[But] it was worth it, if only to go undercover into the male psyche. Because let me just tell you, you are real simple. Even simpler than I thought.

“I walk into a room and before people are disappointed by the marriage and the fact that [my hair] isn’t attached to Sienna Miller or something, they’re like ‘Oh a blonde person with boobs!’”

Feigning despair, she added: “Boys are just aware of a blonde head of hair in the room. I’m positive. I’ve walked this planet as a brunette with total anonymity. And now I walk into a party and people are like, [gasps]’.”

Read more: Girls star Allison Williams opens up about her intimate A-list wedding

It remains unclear as to whether or not this has convinced her to go back to her brunette tresses. However, judging by Williams’ take on the upkeep required to keep her lightened locks looking their best, we wouldn’t be too surprised to see her with a darker shade sometime soon.

“I am exhausted,” she said. “For all of you who have dyed hair, you are heroes. This is exhausting – who knew?

“There’s so much maintenance. It’s a whole thing.”

Images: Terence Patrick / CBS / Rex Features