I'm not familiar with Fedora file locations, but it probably uses *.png, *.bmp, or *.ico for the mouse pointer. The pointer is actually an image file which has a transparent background, which in your case has been modified. Do a search for those file types, probably in /usr/share, /var, or /etc.
You don't say which desktop you're using (kde, gnome, etc.) so can't be much more specific. In the future please provide more information about your system, such as kernel version, desktop & version and anything else which seems pertinent.
Hope this is useful.
Tom (retired penguin)