Crop on negative offsets creates black content

[german970814]

trafficstars

Question

When I try to crop an image with negative offsets, it does fill the "no content" image with black. It does any way to select which color fill? I'm trying to do a cropper like instagram does, and on small images it does crop the image with negative offset and fills this content with white color if "light" appearance is active or "dark" depending on case