GIMP 2.10.24 - How to Create A White Background On A Finger Print

[rich2005]

There are going to be a few ways:

You could try to desaturate using Colours -> Destaurate -> Mono Mixer https://i.imgur.com/cCC4xgQ.jpg
or
Tools -> GEGL Operation -> Color warp (from the drop down menu) Color pick (carefully) bump the weight up to a large value https://i.imgur.com/PgoYQrM.jpg