bought an ivory food color (wilton)only to discover its not ivory as written on it but a different colour after i had kneed it into the fondant! dont know if this has ever happened to anyone else?

Sounds like the color-labelled cap got switched or mixed up. Sorry that happened to you (

Ivory can be very misleading. It takes just the tinyest bit of gel to get the right color. It is *very easy* to over do ivory.
NOw if you ended up getting *brown!* OR black or green then yes, you probably got a mislabled jar. It certainly can happen but not often.