Tie Dye Soccer Birthday Cake

4 months ago I won an airbrush at a cake decorating contest.  Since then I've been scared to use it.   I thought it would be technical to use, messy and I'd need a degree in spray paint to use it, but a tie dye cake doesn't have to be perfect.  As it turns out, it was easy to use and not very messy.  But as for the degree, I could use more practice.  Fortunately, I bought 12 bottles each holding 6 ounces of airbrush color.  When I made this cake I used about 10 drops of each color so I think the bottles will provide plenty of practice...