He's a typical "Silver Dapple". Actually, the proper genetic name would be "Silver Black". That's what you get when a black horse also gets the silver gene. Silver Blacks come in many different shades...ranging from light silvery gray, to very dark brown (almost black) with manes ranging anywhere from a striking silver white....to a darker gray color. Many call the shade your guy is...."Chocolate Silver".
"Flaxen" is a yellow or cream shade. The lightened manes & tails on "Silvers" will have a definite gray or silver hue to them.