Practical guide and verification
What inversion changes
Colour inversion maps each channel to its opposite numeric value. It changes pixel colours, not the semantic meaning of the image, and it is different from simply switching an interface into dark mode.
Alpha and transparency
Transparent pixels can make an inverted image look unexpected because RGB values may exist even where alpha is low or zero. Check the result against both light and dark backgrounds when transparency matters.
Common mistake
Do not assume inversion produces a photographic negative that matches film chemistry or colour-managed prepress workflows. A digital channel inversion is a straightforward pixel transform, while real negative and print processes can involve profiles, curves and material response.