Prism
A colorful unicorn stallion. Surprisingly - despite his color scheme, he is not gay. (I figure he's bi, actually, just isn't interested in finding a special somepony be it male or female; he's more interested in his art then anything) The rainbow mane and tail represent his skilled use of colors. He is an artist. He likes to paint and is very good at it. I figure in MLP universe he sells his paintings for interior decoration.