How to Invert Image Colors - GIMP tutorial

Learn how to invert colors in an image - GIMP Tutorial

GIMP Tutorial: Selective Colouring

How to make digital negatives

4.7. Change the Mode

Gimp: Invert and merge (to remove color cast) - GIMP

How to Invert Colour Film Negatives in Photoshop

How to Invert Colors in Photoshop

Production-Now.com Blog: Tutorial: Isolating Colors in Gimp

Digitising and Editing Film Photos with Free, Open-Source Software – Part 2: Fake HDR - pixl-latr

3 Ways to Invert Colors in GIMP (With Steps & Tips)

GIMP Terrain Design Document - PMC Farming Simulator 19