The This Morning presenter shared her high-street look with her 3.4 million followers on Instagram.
Holly, 37, looked smart and sophisticated in a cashmere jumper from Marks and Spencer and trousers from French Connection.
She wrote: “Morning Wednesday… today’s look on @thismorning…. let go… knitwear by @marksandspencer trousers by @frenchconnection_official shoes by @lkbennettlondon #hwstyle.”
However, fans were quick to notice the mum of three had failed to wear odd socks, an initiative for World Down Syndrome, which falls on March 21 every year.
The idea is that chromosomes look like socks and people with Down’s syndrome have an extra chromosome.
Commenting on Holly’s lack of socks, one fan questioned: “Where are your odd socks @hollywilloughby?”
Another added: No odd socks Holly, hope Phil and the crew remember.”
However, the day before on This Morning Holly and Phil led a similar campaign called Wouldn’t Change A Thing.
Sharing a clip from the ITV show – which saw Down’s Syndrome children and their parents sing on the show – Holly wrote: “This is why I love working on @thismorning… #wouldntchangeathing #worlddownsyndromeday.”