I'm not some kind of Butterfly-maniac :D It just came out this way.
14 big brushes for more free fun & work :)
Quick tutorial: If you want to achieve the same effect as on the preview use white background and black paint for the brush. Create a new hue/saturation adjustment layer over your black butterfly, check "colorize" in the hue/saturation box and then move hue and saturation sliders. Black and white remains the same, but greys...well, you choose :D
Have fun!