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

[tc47]

Hello,

I have a finger print that needs to be on a white background.

I changed the background to white using Quick Mask, but the issue is that the finger print has crests / troughs, and the troughs color is that of the old background.

   

1. Is there a way to resolve this?

2. Is there a way to make the crests a deeper red?

I haven't used gimp in quite a few years and have forgotten quite a bit of what I used to know.
Any help would be appreciated.

Thanks.