You can combine your pens to get more color combinations. For example, you can get green by applying blue and yellow inks over each other. First apply a thin layer of one color until you get the desired coverage, then switch pens and apply an even layer of your second ink. Try making your own combinations!
You need to fine tune the spray nozzle by turning the adjustment nozzle all the way to the negative side (-). Then while holding the trigger down, slowly adjust the nozzle toward the positive side (+) until you get a nice even spray. You should also make sure that the pen is fully inserted by pushing it all the way into the slot on the spray gun until you hear/feel it click.
