Why is a false clue called a "Red Herring"?

I'm not 100% but from what i gather it's because there is no such thing as a 'red herring' but when smoked, herring tends to turn red, so it leads to the false conclusion that herring can be red.So maybe to leave a false clue to lead somebody off in what they think is the right direction, is like smoking a herring and telling people its just a red herring? Hope that helps in some way! i confused myself there slightly!