Viola Davis' hair turned white after a stylist put "goo" in it.

Viola Davis

Viola Davis

The 50-year-old actress has admitted a hair expert didn't know how to tame her natural locks and she had to bite her tongue when a stylist doused her hair in gel used only by "white people" and hair spray, which made her hair shrink and change colour as soon as she stood in the sun.

Speaking about her hair disaster on 'The Late Show with Stephen Colbert' on Tuesday (03.08.16), she said: "Sticky is like, when I was doing a movie and I was doing it with my 'fro and this Caucasian woman had her fingers in my hair, she said 'I'm going to make it really pretty' and so she put some white goo in it ... [the] goo only white people would use.

"She put that and then she took a big spray bottle filled with water and just started spraying my 'fro with the goo in the hair. And I wanted to say, 'It's not going to work,' but I knew if I said it I would be insulting her. So I went to the set and slowly the sun caught my hair and my whole afro turned white.

"Then you go to talk about hair and then you gotta say, 'You don't know what to do with my hair,' but you can't say that because you'd be insulting [her]."

And the 'Suicide Squad' star - who plays Amanda Waller in the DC Comic film adaptation alongside Will Smith, Cara Delevingne and Margot Robbie - has revealed the worst thing anyone could do to her type of tresses is put water on it.

She explained: "By the way, when you put water on a 'fro, if it's this big, it will become this big.

"It shrinks. That's just a little lesson."