Kate Middleton's famous locks betray grey hairs in photographers' flashes

Being a new mum is stressful and tiring for anyone, and when your son is a Prince and the heir to the throne, there's an added element of pressure the rest of us will never know.

So it's hardly surprising that the 31-year-old Duchess of Cambridge has developed a few grey hairs, seen peeking out from her centrally-parted locks.

The former Kate Middleton's white hairs were captured in the flashes from photographer's shots as she joined Prince William and Barbara Windsor at a British Legion event to raise awareness of Poppy Day - otherwise known as Remembrance Sunday.

The images show what appears to be half an inch of root growth that's not a glossy and deeply coloured as we're used to from the Duchess' mane, suggesting she's due a hairdresser's visit.

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Going grey is, of course, a perfectly natural part of the ageing process and most of us will start to notice the odd white hairs from our 30s onwards, however Kate's a little early as the average woman doesn't start to go grey until she's around 35.

But then, the average women doesn't have the eyes of the world and the media lens trained on every follicle.

Catherine spent most of the summer cosied up indoors with her family and newborn son George, so now the she's is back on royal duties, we're back to seeing her in her trusty autumn wardobe again.

And showing that she's no spendthrift, Kate opted to re-wear an old favourite from her 2011 AW collection - a dark red L.K. Bennett coat with belt, as she road the bus to High Street Kensington station.

We wonder if the choice of a red outfit was down to Kate's supposed new stylist - school friend Emilia Jardine-Paterson - who's reportedly been trying to edge Kate's style towards more colourful and brightly-patterned choices, instead of the Duchess' trademark neutrals.

But it seems likely that this choice was all Kate, as red and maroon tones appear to be a favourite of the Duchess, who's often seen wearing rosy hues.