Its easy. All you have to do is press the beginning letter of the color on your keyboard. (B,P,R,O,Y,W) Then balls will come up! Warning: you can only have up to about 300 balls, so I added a restart button! Thx!
I made this after I made a cool little ball drawing game called Rainbow Art!: The Art that Never Stops! So, be sure to check it out! I'm thinking about making another game like a collage type thing. I've made one before, but sadly didn't save it! :( Anyway, I hope you enjoy this little project. Please report any glitches and stuff like that! Thx!