Force the black lines on a sprite

[CodeHunter]

Once again I have a question. I was playing around with my sprites and notice how everything in black is erased from the screen. I know this isn't a major problem unless you need some areas to show black. My question, is there a way to set the sprites background to a color and force darkbasic to erase the background color that you set so that you can force the black lines you have for your sprite? If not I can carry on with giving it an off set color of gray. If anyone has information please let me know.
Thanks