Changing color

[Dawnofdreams]

So i got gimp and i tried to hue saturation. But when i do that for sum reason the background color change to. So when i put in it my game there is this black thing surrounding my item.So, then i have to go back and delete the surrounding color and hopefully not make a mistake and erase part of the item's image. But it take very long and am tired of doing this process . Is there a easier way to remove that extra surrounding color?

[Anna Comnena]

If GIMP has layers, magic wand select the pure black background (make sure the selector tool only chooses that color and not near colors). Then save that as a new layer or in new document. Then do whatever hue and color changes, then paste the clean black background back in.