Invert Image Colors

Photograph an old negative on a light box or a bright screen and invert it to see the picture as a positive. Black and white negatives come out well straight away. Colour negatives have an orange base, so the result may look blue; use a photo editor to correct the colour balance afterwards.

Inverting a white diagram or a screenshot of a document gives a dark version that is easier to read at night or fits a dark slide. Lower the strength for a grey mid-tone instead of a full negative. PNG images keep their transparency, so an inverted logo or icon can be placed straight onto a dark background.

Every colour is turned into its opposite on the colour wheel: red becomes cyan, green becomes magenta and blue becomes yellow, while black and white swap and middle grey stays almost the same. Skin tones turn bluish and skies turn orange, which gives the familiar look of a film negative. Inverting twice returns the original exactly, because 255 minus (255 minus a value) is the value again.

The strength slider mixes the inverted colours with the original. At 50 the two cancel out to a flat grey, so values between 60 and 90 give a softer negative, and full strength gives a true negative. Transparent parts of PNG images stay transparent, and the result keeps the full resolution of the original. Choose several images to invert a whole set of scanned negatives or diagrams in one go and download them as a ZIP file.