Nainai Kagoyuchi
I have a picture I wanna use for coloring, but it doesn't have a transparent background >8I So annoying.
Just open it in a program and make a layer under it. Color the bottom layer a color so you can see any white spots later. Then go back to the top layer that has the image and use the wand tool, or any tool that selects a area, and select parts of white and delete. If any white dots are left over, take either the wand or an eraser and get rid of em.
It can be a pain. xD