Why is a Red Herring Red?

Book excerpt: Blame it on my father. He was a great bloke and all that but he was also one hell of a contrary bugger. He’d contradict anything anyone said just for the hell of it. He’d even disagree on the weather which, let’s face it, is the one thing upon which everyone always agrees. Anyway, along with the old man’s bloody gout and his double chin, I’ve clearly inherited his predilection for looking at the flip side of just about everything. So while the rest of the world strains to hear the latest news on the perils of smoking, I’m the one saying, “yes, but what are the benefits?” But I haven’t just been pondering my own queries: friends and readers of my columns in magazine and newspapers have asked me such posers as Do TV Detector Vans Really Work, Why Do I Need A Cigarette Before I Can Have A Crap, Is It True That Keith Richards Used To Get His Blood Entirely Replaced, Are You Better Off Running Or Walking Through The Rain, Do Two Wrongs Make A Right, What's The Kindest Way To Tell A Friend That They Have Halitosis, Do Women Who Live/work Together Menstruate At The Same Time and Why Is A Red Herring Red?