It's Blue/It's Black, will give you all the true tones of a dark indigo blue, and if left in the dye long enough will turn black/blue. Unlike my other color, Deep Blue Sea that stops working at a dark Navy, It's Blue/It's Black keeps on getting darker until it turns black. Caution if egg is left in this color too long or if the shell is porous you may get a bronze finish or semi luster to the shell. This can be cleaned off if the look is undesirable by using a vinegar bath then Ivory Dish Detergent, or a quick dip in The Works. Then you may re dip the egg.