It is has become famous for cakes and hair to be colored starting with the dark hues of one color at the bottom of the cake or hair, and then it becomes lighter as you go up the cake or hair. However, the color itself is the same. For instance, there are two types of this type of styling. One is called balayage, and the other is called ombre. Ombre is probably the more recognized term for this type of styling.
The main difference between the two types of styling is that there are prominent lines between the hues. There is a more subtle transition between the coloring hues in balayage. Also, the ombre hair of cake is supposed to be more striking than balayage.