Colorsplashing is a technique used to alter the colors of things or people that are in range of a flash. When you colorsplash, you use a flash with different colors to bathe your subject with colored light. You can do this by using a Colorsplash camera or attaching a Colorsplash flash or a Diana+ Flash on the hotshoe of your camera.
Be aware that this technique will only work on subjects that are within reach of the flash. If you take the picture of a dog in the street using the blue gel of your flash, only the dog will be blue and not the background. This is because the flash is not strong enough to reach more than a few meters from the camera.