The actress attended the Novak Djokovic Foundation London Gala Dinner on Monday night in a floaty gunmetal gown teamed with a swept-back updo that revealed a darker shade than Hudson's usual bright colour.
So - has Hudson swapped blonde for that on trend in-between shade, bronde? If that's the case, then she's chosen the wrong time for the big reveal. Sorry Kate, the nation is too busy admiring Kim Sears and her shiny locks right now.
On the other hand, if she's forgotten to get her roots done and swept her hair up in an attempt to hide them - well played! The trick worked.
Like Kate's latest style? Here's how to do the easiest updo of them all: