Flip every colour to its opposite for a negative, or invert just one or two channels for cyan, magenta and film-style effects, with an amount slider to dial it in.
Subtracts each colour value from 255, so black becomes white, red becomes cyan and a mid grey stays roughly where it is. With Amount below 100 the pixel is moved only part of the way toward its opposite. The three channel switches let you invert red, green and blue independently: flip only red and the image shifts toward cyan, flip only blue and it takes on the warm orange cast of a scanned colour negative. Transparency is never changed, so cut-out logos keep their edges.
A 1920 × 1080 screenshot of a dark code editor, mostly #1e1e1e background with light grey text, inverts to a #e1e1e1 background with dark text, which prints on about a tenth of the toner. A pixel of pure orange (255, 128, 0) becomes (0, 127, 255), a sky blue. The same pixel with only the blue channel inverted becomes (255, 128, 255), a pink. A 4 MB JPEG portrait comes back at about the same size, because inversion moves values but adds no new detail for the encoder to store.
Use it to convert scanned negatives into positives, to turn dark-theme screenshots into printable light ones, to create quick posterised artwork or to check contrast in a design by viewing it flipped. Combine it with Grayscale Image for a monochrome negative, or with Adjust Hue to correct the orange mask of colour film. It is not a way to make a photo lighter or darker; for that use Change Brightness, because inverting swaps highlights and shadows rather than shifting them.
Amount at 100 is a true negative; 0 leaves the image untouched. Red, Green and Blue choose which channels flip. Two channels on gives a colour-negative look, one channel on gives a duotone-like tint. Output Same keeps the original file type, and Batch mode applies the identical settings to a whole set of scans so a roll of film comes out consistent.
Will inverting a film negative give me a correct photo? It gets you most of the way. Colour negatives carry an orange mask, so after a full invert the picture looks blue. Run Adjust Hue or Adjust Color Channels afterwards to neutralise it; black-and-white negatives invert perfectly in one step.
What does 50 percent do? It moves every channel halfway to its opposite, so the whole image collapses toward mid grey. Values near 50 are rarely useful on photos but work as a low-contrast base for text overlays.
Why is my inverted PNG still transparent in the same places? The alpha channel is left untouched on purpose. Only red, green and blue flip, so a logo with a see-through background stays see-through.
Does this work on dark-mode screenshots? Yes, and it is a common use: a screenshot of a dark app inverts to a light one that prints without draining ink. Text stays readable because inversion keeps contrast, only flipped.