How to make a easy rainbow cake

With holidays coming up I tried to make everything hand made for my sons birthday party. That included his cake. He loves colors and all he wants was a rainbow cake, so off I went to try to figure out how to make one. I found it was a lot easier then I thought. To make one all you need is white cake mix(ready to go, so make the cake mix like the box says)  and food coloring. After the cake mix was made we split it up into few different bowls and mixed food coloring in. After that we poured them into the pan and baked. (we followed the baking directions as the box said) Our cake when done got a little darker on the top but stayed very bright inside. My son and daughter both loved being apart of the process and enjoyed how colorful it was.