Wedding cakes  are my specialty
Are you a baker of some sort? I've heard that modern wedding cakes are often more of a centerpiece than a food item, and sometimes they're not even eaten!
I always wonder if people actually ate the wedding cake
Well traditionally they were made to bring good luck to all those who attended the wedding, so I assume you were supposed to eat it originally.
who came up with the tradition of the wedding cake?
I'm not sure to be honest, maybe it was a religious tradition. I do know that wedding cakes often use various ingredients like fondant, buttercream, chocolate, and marzipan, sounds delicious.
i guess the tradition wedding cake is white but would be neat to see other different color cake.
the couple. Marzipan, fondant, gum paste, buttercream, and chocolate are among the popular ingredients used. Cakes range in price along with size and components. Cakes are usually priced on a per-person, or per-slice, basis. Prices can range from a few dollars to a few hundred dollars per-person or slice, depending on the pastry chef who is hired to make the cake. Wedding cakes and cake decorating in general have become a certain pop culture symbol in western society. In the United
decoration was appeared, they were often at least partially three-dimensional, were colourful. However, since some decoration were made in a variety of substances, sometimes the decoration or even parts of wedding cake were inedible. In The myth that eating the pie would bring good luck was still common but the glass ring slowly died out and the flower bouquet toss replaced it.
Fruit cakes were a sign of fertility and prosperity, which helped them gain popularity because married men wanted to have plenty of children. 
History Modern Western