So you can imagine Diary's surprise when we discovered that the Karmarama planning chief, and wearer of infamously garish shirts, had hung up his floral get-up and become a style advisor on the telly.
He was joined by fellow fashion novice Dave Buonaguidi, the chief executive of Karmarama, who had taken time out from threatening burglars with spades to join McGrath in his new enterprise.
This week, the nation watched the pair team up with the TV fashionistas Trinny and Susannah for the latest episode of Undress the Nation. But for those who didn't see the show, you'll be relieved (or not) to know that the Karmarama duo were spared the humiliation of one of Trinny and Susannah's unceremonious disrobing sessions.
Instead, McGrath and Buonaguidi helped the ladies develop a "highway code"-style set of rules for fashionably challenged men. The rules included how to dress if you're short or tall, and even how to flatter one's man-boobs.
After hours of creative brainstorming, Trinny and Susannah hit Oxford Street with Karmarama's newly developed dress code.
It's just a shame that their target audience, tracksuit-wearing pub dwellers, were thin on the ground - no doubt too busy necking pints and watching football to take note of McGrath and Buonaguidi's valuable advice.