(Picture - 3 News, Sir Peter Snell with his favourite design)
We've been asked "Why is the fern white and not silver?"
Quite simply, in heraldry and vexillology, white is used to depict silver on a flag. Yellow is used to depict gold in the same fashion.
White and yellow are 'metals' and are used to separate colours on a flag.
Thought our history the silver fern has been depicted in white, besides, light grey would quickly fade to white when used on a flag.