You have a few choices
Just For Men
Grecian2000
Schwarzkopf Men Perfect Hair Colour
Maybe there's more.
My advice - subtlety. If you are completely grey. Restore your natural hair colour gradually, not in one dying session - like Alan Hansen.... That way, people may forget you were ever grey.
Silver looks good, when all the hair is silver. Its when you have a real mix of colour & grey that it looks a tad weary.
Though tbh grey better than bald, and there's far better things to worry about!