I photographed the milk science experiment. Basically here is what's happening: the soap is a degreaser so the molecules in it are attacking the fat in the milk, causing motion which creates the swirling of the colors. Where the colors meet, they combine & form new colors. Science is great! If you wish to try here is what you will need.
Milk, liquid food coloring, dish detergent & q-tips
What To Do:
Pour some milk into a bowl then add drops of the food color to the milk. Dip the q-tip into the detergent then into the milk or just drop small drops of the detergent into the milk directly.